Hi, a technical question, up to how many plugins Osclass remains efficient? i.e. if I install 30-40 plugins could there be problems of some kind?

A none issue with http2 and the imminent wide adoption of http3.

Also, core is optimized to handle db queries from multiple plugins simultaneously without impacting performance. Redis is still recommended for minimizing db queries. As I stated in other posts, PHP is CPU-bound so shoot for 2.5Ghz+ when clustering and preferably 3GHz+/16GB to 32GB RAM for AIO single VM usage.

I have 50+ enabled currently.

We've been testing with 180 plugins and performance between same site using 0 plugins and 180 plugins could not be spotted.
If you would be using 200 plugins where each can have heavy load on database (like attributes), you would spot difference.