Hi @UbikMZ! I want to emphasize what Osiris has said - there are a lot of people here working hard on their spare time to give you help for free. For my part, I do apologize for the late notice you receive about TLS-SNI deprecation. And as tdelmas said, you’ve actually got a lot longer than you think - you’ve got 90 days from the issuance of your last certificate, whenever that was.
It sounds like you have particularly in-depth needs for support, so you might benefit from paying a commercial CA for a certificate and using their paid support.