I went though the same thing with many plugins I had written. I didn’t have the bandwidth to modernize them to the Discourse standard. I have a data science-type job so while I know software engineering concepts, I don’t keep up-to-date with the specifics of web dev stuff. In the end I didn’t update my site for 8 months because it relied on these depreciated plugins.
I don’t want to trivialize your struggle, but basically I think with the advent of agentic coding, this development pace has become a non-problem. What would have taken me a week or two to fix and get right took a $20 Claude Code subscription and a couple minutes per plugin. Not only that, but I was also able to optimize them for performance. After using agentic coding for a few work and hobby projects, I don’t think I will ever code something from scratch again in my life. It’s like the technological difference between writing and delivering a letter by hand versus sending an email. It’s a bit sad but yet at the same it feels like you’ve been gifted god-level powers.