It was mentioned in another thread that kits sometimes had a protein haze, so early addition of bentonite fixed that. Supposedly it's not a current problem.IMHO Bentonite is useless. I haven't used it in over 2 years and have noticed no differences, except less lees. I used to only make Mosti kits and they stopped using Bentonite 2 or 3 years ago, so there was my justification to stop. George, at Fine Vine Wines, agreed. Bentonite comes in a kit? I throw it away. YMMV
Looking at this from the POV of kit vendors, the early addition of bentonite helps with clearing the wine on kit wine schedule -- if the customer is trying to bottle in 28 days, it's insurance that the wine will clear. The process has to work on the first try, else there will be no repeat business.
Everything in kits from reputable vendors makes perfect sense, if viewed from their POV.