How to set up an Android phone for comfortable work with clients (silencing incoming calls after hours, silent mode, etc.)?

Question

Android

How to set up an Android phone for comfortable work with clients (folding into the background of incoming calls after hours, silent mode at night)?
I am a freelancer, I have been freelancing in the Russian market since 2011.
The question is how to set up an Android phone for comfortable work with clients.
I use e-mail and telephone to communicate with clients.
I don’t consider the option to remove the phone from the site, because this is not a solution to the problem - and this will cut off 50% of orders and income.
Where the phone is located, I also have working hours Mon-Fri 8:00 - 17:00 Moscow time(yes, I can sometimes, on my own initiative, as an exception, work outside working hours - to, for example, finish some project - but of course, no receiving calls and no solving urgent problems outside working hours - otherwise you can go crazy).
And at first everything was more or less good (in terms of personal time).
But then professionalism and income began to grow, and the client base also began to grow. And there was such a phenomenon as calls during non-working hours (for example, at 22 o'clock, and in especially neglected cases - at one in the morning) . The client believes that, of course, if he has something covered there, he can call at 18 o'clock or at 23 o'clock or on a day off and I will be happy to deal with his issue.
You can’t earn all the money and I see no reason to work more than 8 hours a day, 5 days a week.
1) The first solution was to install the LLama program, which automatically cut off calls after hours . That is, the phone was automatically switched to silent mode and in the event of an incoming call, for example, at 6:30 or 19:30, the phone will not disturb me and I can enjoy my vacation as if nothing had happened.
It really cut off some of the problems. With the growth of the client base, I realized that it is impossible to live without this program.
But not all problems. The phone now does not bother me after hours - but still the phone is a universal device and I still use it as a GPS navigator and as an MP3 player, as well as for the Internet or reading books. And I don’t need the book to start ringing on the day off on the day when I rest and read quietly.
When a call comes in, the phone behaves quietly after hours - but the incoming call screen takes up the entire screen and does not collapse, which paralyzes the device. That is, while there is an incoming call, I cannot use the device normally. Even though it's after hours and I don't have to answer. I don't want to drop calls. It is necessary that the client thinks that no one picked up the phone - but that he does not think that the call is deliberately dropped.
I was looking for different non-standard programs for receiving calls - there are also those where the incoming call screen can be minimized - but there is another problem. Namely - if in a standard dialer to accept / reject a call you need to swipe your finger along a certain trajectory - then in these applications, as a rule, to receive or hang up a call, it is enough to poke at a certain place on the screen. And there is always a risk that with the active use of the device with an unexpected incoming call, you can accidentally accept or reject it.
And I didn’t find such programs so that the screen of an incoming call is minimized, while in order to receive a call it was not necessary to poke at a certain place on the screen, but to swipe my finger. Yes - I returned to this issue 3 times - I downloaded and installed a bunch of programs - but there was no sense in them. Perhaps only the Call PopOut program is suitable - but for some reason it does not remove the InCallUI incoming call screen.
In the end, I found a combination of programs - FullCalledId + CallPopOut + LLama - which, together and somehow through one back seat, allowed me to minimize the incoming call screen (and not show the InCallUI screen) in 7 taps on the screen - but this, of course, is inconvenient . If you read a book on a day off - to do 7 clicks with each incoming call is boring in itself. That's why I don't use this option.
What I'm doing now (as a temporary, I hope, solution to the problem):
1) On weekdays at 17 o'clock every day I turn on the "Flight mode" mode on my phone. At 23:00 I turn it off (I still need to sleep, and incoming calls after 23:00 will not bother me, since LLama sets the silent mode). For 6 hours I can safely use the phone without any incoming calls (although without the Internet - but what can I do). And so every day.
2) On Friday evening, I rearrange working SIM cards (2 pieces, one of them has the Internet) to another phone (I bought a cheap one for 3000 rubles especially for this case) so that it registers missed calls (to call back on Monday). I insert another, specially purchased SIM card with the Internet connected into the main one.
I always take 2 phones with me - one (which registers incoming) usually just lies in my pocket, I actively use the second one.
The disadvantage of this solution is that you have to pay for 2 Internet - one on a working SIM card, the other on a SIM card for the weekend. Turning off the Internet on a working SIM card will not work - because on weekdays I can leave the house and I constantly need the Internet to work with clients. And I have two working sims.
That is, there are no simple solutions to the problem.
What I want.
It is necessary that the incoming call be folded into the background (not rejected!) With one movement. And ideally, the incoming call window should not appear on the screen at all during non-working hours, while it is necessary that missed incoming calls be recorded in the incoming log(so that you can call back on Monday - do not lose customers). But at the same time, it is NOT NEEDED that notifications of missed calls be displayed at the top of the screen. That is, so that during non-working hours when using the device, nothing reminds me of clients and work. But at the same time, so that I can check the missed calls myself if necessary and not lose customers, and also so that there is no need to rearrange SIM cards, carry a second phone, pay for 2 Internet and other nonsense.
I tried to stop the InCallUI process, including during the incoming exit using LLama, etc. - nothing helps. But I'm sure there is a solution.

Answer 1

Voice mail as a carrier service (conditional forwarding to voice mailbox)?
And the client can leave any information, and you can decide who to call back and who not to call back (or not to call back at all), without letting the opponent know what decision was made (and whether it was made at all).

Answer 2

1.Purchase a landline number via sip and put an asterisk with IVR
2. Alternatively, offer paid calls to 8809 or paid support at a triple rate during non-working hours.
Naturally, negotiate with clients: I don’t pick up the phone from 17-00 to 7:59 and burn in hell, even if everything is covered.
I think the flow of calls and customers will immediately fall.
Putting myself in the place of the customer, I would have terminated the contract on the second day if my calls failed and the contractor's work schedule was not specified in the contract.

Answer 3

A little offtopic
I have a dual-sim smartphone on Android. One sim is personal, the other is work. Sometimes the phone itself makes calls, calls customers very inopportunely. Nobody faced it? Googled, many have the same problems, but did not find a solution anywhere.