I used front squats on 5/3/1 for a good amount of time in the past. It worked, but ultimately, back squats are a better choice because weeks 1 and 2 on 5/3/1 can sometimes be too high of reps for the front squat. A lot of people's upper back/rhomboids will fail stabilizing the weight before their legs are fatigued, so that's why you should stick to the lower reps in front squat. The sweet spot, I think, is reps in the 2-4 rep range.
The learning curve is not that big for the F. Squat, you just have to get used to it. Once you start front squatting 275+ lbs, you'll start to see some serious meat on your quads, glutes, and hams. Shit, even your calves.
Edit: just make sure you go ass to grass. there's no other way. There's also not really a need for a belt on front squats, unless your core stability really fucking sucks.