A follow up from wcass's successful combination of the regular and split right shift PCBs into one, so that the PCB can be used by both options (this was done several years ago and is used on all of the current production boards):
Now I am thinking of combining them for the top inner assembly, as there have been requests for flexibility between HHKB style and non-HHKB style split right shift.
I've attached a combination of the two barrel positions for each of the two split right shift area keys, one showing the overlap and one the finished result with the intersecting area removed. The board could be made as shown in the second image below, with the overlapping cuts removed and left as part of the hole for the barrels. Since a majority of the hole has borders for each of the two keys that will contact the barrel and hold it in place, I'd guess that there would be little movement possible in the North/South/East/West direction. For the non-HHKB shift position, since the locking tabs would not be present, there would be a risk of rotation, but the barrels surrounding these keys should minimize rotation. For further risk avoidance, maybe a small plastic rectangle can be placed between the two shift barrels (not sure if needed or recommended since the barrels should be held in place with the surrounding barrels). Additionally, the shift key itself connecting both barrels might restrict movement to avoid issues during operation in normal right shift.
What do you think? Can wcass's idea be added to the top inner assembly plate?

