I think this "* The software is pretty specific to my requirements." is the biggest part for me. I built something with Antigravity over the holidays that I can use for myself and it solves my use case. I tried thinking about if this can be helpful for others and pushed it a bit further into a version that could be hosted. Which does not make that much sense because it is a computationally intense numerical solver for thermal bridges and just awfully slow on a free hosted platform. But the project was a couple of evenings and would otherwise haven taken me half a year to complete (and thus never been done).

https://github.com/schoenenbach/thermal-bridge https://thermal-bridge.streamlit.app/