How to choose acquiring for individual entrepreneurs to work with most countries?

Question

Payment systems

There is a SAAS platform with clients (physicists) from different locations, mainly Europe and the USA. With the advent of new functions, there was a need to accept payments online (now everything works for free). The average check is expected to be around $9. Payments are not recurring. As possible actions, the registration of a company in the EU (Estonia), and the connection of a human solution like Klarna, or registration in the USA (including participation in the Atlas program) were considered. However, with the current (zero) turnover, it was decided to postpone this option until reliable data on the solvency of the business were obtained. At this point in time, there are several options available:
Signing up with PayPal for Express Invoicing is a high percentage but strong brand awareness and 99% that a card from the farthest corner of the planet will be successful. In the vastness of Runet, I often met the opinion that it was not necessary to work with PayPal, but I did not see an explanation for this.
Update 1: The reason lies in the rate of mandatory currency conversion into rubles when money is received into your accounts. This course is so bad that some people choose not to work with PayPal at all.
The second option is to connect payments through an aggregator. For example, Ya.Kassa. The site says that the money comes in the same currency in which the payment is made on the site. It's cool, but it's not very clear where they come from and what's with the currency control - won't you have to run to the tax office for every five bucks transferred. Withdrawing an amount from $1800 or a month after the last payment is inconvenient.
The third option is to work directly with a bank, such as Tinkov. All algorithms are well described on the site, you can customize the appearance of the payment form yourself, there are 3ds and more. There is no interaction with currency control, because the bank converts the currency into rubles. Of the minuses - I'm sure that the conversion rate will be the most miserable that can be. It is not clear how much the buyer pays in the end - after all, payment will be made in rubles. Countries are connected by proving the presence of users from these countries (lol). In general, there are still more questions than answers.
Update 2: Option 4
Work through the international Paygate, and receive currency transfers to your currency account assigned to the individual entrepreneur. Currently looking at:
www.paddle.com
www.paymentwall.com
Any experience would be appreciated.

Answer 1

One is not enough.
Almost international services have 2 or even 3 or more options for accepting payments.

Answer 2

Registering with PayPal for Express Invoicing - high percentage but strong brand recognition and 99% that the card from the farthest corner of the planet will be successful

I would not count on it, because in my practice it is just the opposite, PayPal is very picky. Check out Stripe.

Answer 3

paymentwall.com
xsolla.com

Answer 4

It seems to me that Internet Acquiring for the legal work of an individual entrepreneur must be located in the Russian Federation.
So far, I have found only these comrades in the Russian Federation: https://acquiring.ru/internet-acquiring/faq/
- an attempt to work with them stopped at the fact that they have been silent on my request for more than a week. Perhaps they are interested in big business.