Quoted from lanfeust:
thanks guys! I have noticed that the mini playfield has difficulties to raise. In test, when the playfield is in upright position, it's fine, but when it's down, the mini plfd, sometimes gets stucked, looks like it's too heavy for itself... so I am pretty sure, this bracket was removed because, it was slowing it down...easy solution...
Sounds very similar to the way the MPF in mine behaved when I first got it. Turned out that the main drive gear in the gearbox had worn down the mating surface where a smaller gear was pressed into it causing it to slip when any real load was placed on it. So coming down was good, but raising it up was dodgy. The reset roller bracket, while not being a major part of the issue would have contributed a little extra load at the beginning and end of the cycle so I can see how someone might have jumped to the conclusion that it was causing it.
My fix was to disassemble the gearbox and braise the gears (both metal) together to eliminate the slipping. Some people questioned that choice the first time I mentioned it, but those gears were not intended to slip in the first place so it is a valid (IMHO) approach to the repair. And I've had no MPF issues of that kind since. Probably at least five years now. YMMV