Great idea. I use them all the time with people. Regarding assistance lifts, I recommend anything that improves your quad strength. It will help balance out the whole hamstring thing.
Assistance lifts are nasically a never ending see-saw. You go with a few until you fix your weak spot and find something else holding you back, then rotate them to address that issue.
I follow a modified Juggernaut template, after having followed 531 for a few years. Juggernaut crushed me the first time, because I was trying to back squat and deadlift in the same training week. Going back to it after switching to front squats made it quite a bit more manageable (being on TRT def helps as well, haha).
That being said, I have two lower body days following the program - deadlift day and front squat day. I also use Boring But Big from 531, so I do 5x10 on opposite days, ie, 5x10 front squats at 50% training max on deadlift day, and vice versa. On front squat day, I will do leg extensions after deadlifts for assistance work (supersetted with some form of calf training). I’ve tried different quad-dominant assistance moves (BSS, rev lunges, etc), and feel I get the most bang for my buck from leg extensions.
Following BBB front squats on deadlift day, right now I am doing RDL’s for assistance - just 3x8 but going up in weight each week as possible. For a while I didn’t do any ham assistance work, since I am usually pretty beat after the first two moves. I may try some different stuff in the future, but not sure what to try. Hams have always been a hard one for me to hit (ie, make sore). Just got back to work (deployed), and we have a glute ham raise, as well as a reverse hyper so I may try throwing those in periodically.