Sure but the OP suggests that these were minor gains, and that this limited scope for gains was necessary in order to preserve the quality standard that's long been expected in that FLOSS community. We aren't talking about either a 10x productivity gain or one-shotting entire new features from scratch.
This is arguably a key quote: "Then, it was time to read all the code, line by line. ... I found many small inefficiencies or design errors ... so I started a process of manual and AI-assisted rewrite of many modules." We should not underestimate that step: reading code line by line might easily require more time than writing it from scratch.
Sure but the OP suggests that these were minor gains, and that this limited scope for gains was necessary in order to preserve the quality standard that's long been expected in that FLOSS community. We aren't talking about either a 10x productivity gain or one-shotting entire new features from scratch.
This is arguably a key quote: "Then, it was time to read all the code, line by line. ... I found many small inefficiencies or design errors ... so I started a process of manual and AI-assisted rewrite of many modules." We should not underestimate that step: reading code line by line might easily require more time than writing it from scratch.