Yes, I found out my Diamond Elite VIP benefits (4 Front of Line passes per visit, 50% off food) from Magic Mountain also all worked at Knott's. The 50% off food even included a specialty food item for the Peanuts Festival, so I'm curious if it will hold for Boysenberry Festival Tasting passes (I'm guessing not... even when SFMM did the Foods of the World tasking pass, while there was a discount, it was not 50%). But it could work on individual, off the tasting card items.
Also, to get the paper FOL passes, we had to scan once to get 2 passes, have them printed, and then rescan them again for the other two. While at SFMM (at least as of a couple of weeks ago), they had to scan and print my passes four separate times. I've also heard you can just get your mobile pass barcode scanned at the Fastlane entry points, which is also convenient, so that you don't have to print out anything... but I like having the paper ones so I don't lose track of how many I used, and I also usually give any unused ones to other park guests to get some good karma.
I also saw a random report from a source I don't know, so I'm taking it was a grain of salt, but it claims that they are now letting guests wait up to the carousel area before entering the park in the morning, and that early entry can get in as early as 10:10.