I have one as well (the version with the thermowell) and have had no issues sanitizing the valve assembly.
I soak it in an Iodophor solution while opening/closing the valve a few times prior to filling the fermentor with wort. When it's time to rack to the serving keg, I spray Iodophor solution up into the valve and all around the valve exterior. I think I've run about 10 batches through it so far.
I have never done it, but I understand that the valve can also be fully disassembled for cleaning if desired (someone posted pictures of this on another forum). It can also be boiled.
Given what you have stated in other threads, I don't think you actually care about this, but here's a thread I started that shows how to rig up a gas post to a drilled stopper so that one do a closed loop transfer into a CO2 purged keg. https://www.homebrewersassociation.org/forum/index.php?topic=20241.0
The o-rings that are used to attach the racking arm to the inside of the ball valve are small and pretty fragile. You may want to order some extras right off the bat (you can probably get a bag of 100 of them from McMaster Carr for less than you can buy a replacement set from the manufacturer). My experience has been that if you direct the initial runoff into a collection jar it will start to run clear right after you get enough for a hydrometer reading. It can then be re-directed into the serving keg without the need to ever rotate the valve/racking arm assembly out of the trub.
I'm happy with the fermentor and would buy it again.