TBB sandboxing is a great hardening measure. I was wondering if there are side-effects such as breaking setups that involve using anonymous networks other than Tor. Such as: https://thetinhat.com/tutorials/darknets/i2p-browser-setup-guide.html
As a workaround we can document how to toggle the TBB variable to disable this. Of course the best solution is having the isolation compatible with alternative setups if you consider this (minority) use-case worthy of your effort.