Does it make sense to order IP for SSL certificates?

Question

Digital certificates

There are 3 sites on the server, everything is fine with the first site, but with the other two:

Этот сайт работает только в браузерах с поддержкой SNI.

I read today about the whole thing, I receive certificates from Let's Encrypt, I set everything up, all domains have an A + rating. But the message about SNI pops up.
I also read about browser support, and it seems to be not critical, as I understand it all due to one IP for all domains and their subdomains.
Basically, additional ip are not so expensive and let's say 2 ip is quite possible to buy, but is it worth it? Does this make sense?
And another question, will it work on subdomains? Or do they also need to buy an additional ip?

Answer 1

https://firstvds.ru/technology/free-ssl?from=334557

Answer 2

Modern, and even not very browsers have normal support for SNI
IE starting from version 9 of
Safari from version 6 (I can be wrong here)
You don’t have to worry about MSEdge, chrome and FF users at all, these browsers are automatically updated and quite quickly implement new standards
About LE, you can issue one certificate for a large number of domains and their subdomains and this is not a wildcard, a wildcard is a certificate for a domain and any of its subdomains
Personally, I see no reason to spend money on additional IP