- There are rules, and clear established practices that allow you to follow these rules. In software the rabbit hole goes so deep that your average developer cannot even be aware of all the risks.
- You do not have to rely on millions of lines of code you have no control on.
As a simple example, if you are using network communications, you are probably using OpenSSL, GnuTLS or one of the few other TLS implementations. All of them have regular security issues, and simply selling support on an Open Source software you built using one of them will make you liable for these issues. There is no choice: you need TLS, and you're not going to implement it yourself. What are you supposed to do?
The fact that a solo developer selling 100€/month of support is treated the same way than a billion dollar company demonstrates the complete insanity of this act.
But they're not treated the same way. Both by the law itself and the standards courts and regulatory agencies use throught Europe.
As I read it, and with the caveat that the exact requirements are not yet determined: You will need a SBOM stating you use openssl, and how you plan to update openssl if it contains security bugs.
Update: found it, paragraph 46a: In relation to small and micro enterprises, in order to ensure proportionality, it is appropriate to alleviate administrative costs without [...]