I just rooted and s-off'd my one max international. Took a few minutes following a guide on here, I had to us 'firewater' not 'rumrunner' to get s-off. Haven't tried any Roms as I think the stock software is fine, if your worried about sense then install a custom launcher and you almost won't notice the difference between sense and AOSP, even the Google experience launcher is in the play store and works well. The reason I rooted was for write access to the SD card.
Its a great phone with beautiful screen and good battery life.
Not really what your looking for but that's my 2 cents worth
Sent from my HTC One max using XDA Premium 4 mobile app