I've completed the motor install (although i may be missing parts on the motor related to this, the set key that holds the pin in place was missing, found an m4 for now that seems to hold it but the pin doesnt go in fully, see this thread for more details)
First issue (or maybe not), when i push the motor and it moves up, i think when the panel that has the band through it goes under the first panel, half way up, it sticks for a half second, flexes and pops and keeps going.
After this at times on the way up, even during the first half, sometimes the motor stalls briefly.
The biggest issue is after its up fully and you bring it down, the first 16" or so going back it stalls and moans repeatedly, however, interestingly i can work it forward by doing an on off real quick multiple times, OR by pressing upward on the motor.
Here is a video clip of the stalling (most of it near the end):
At this point i took all the wheels off the rear, added washers, so now they have quite a bit of flex available. The retention bracket is installed, but i had my son work the motor while i pulled back on the bracket and wheel on one side only, no change.
When you pull the panels in the rear when its up there, apart, you can see grinding marks on each panel on the sides.
So at this point i'm left with removing the retention brackets on both sides as a final test, and to be able to get the panels apart to add antifriction tape someone recommended.
It appears the front panels will need to come off (not the rear solid non moving one), then apply tape as here: