Hi,
JDM is the Japanese models imported into the UK.
I just wonder if the roller bearing may put a load against the large white plastic fixing that holds the window in place because I think my window shattered from tension between where the roller bearing is and the white fixing that holds the window in place.
After the window shattered I dismantled the white plastic window holder from the frame and discovered that the small bolt you see at the bottom of the white plastic holder was packed out with washers, I'm just guessing it was done at the factory as I haven't touched it.
I would add this is just a suggestion about what could happen, I think your idea looks very good and I'll look forward to your updates