This version is painfully slow for me. Yet, starting with a clean profile seems to do the trick. Does anyone know how to troubleshoot it so I don't need to lose

This version is painfully slow for me. Yet, starting with a clean profile seems to do the trick. Does anyone know how to troubleshoot it so I don't need to lose all my configuration. I have only 3 addons, but 5000 tabs/21 windows. Also a decade of random about:config tweaks which I suspect are the cause. Issues started with version 87 but got a lot worse today. (I'm on Ubuntu with mozilla.org binaries, Intel Haswell) Thank you Mozilla! edit: this is so bad I can't even scoll through about:config to take a look. Typing this text has a >1s delay. Looks like I'm going to need to bite the bullet.