Thonk here in the UK does nice smooth Alpha pots in round, D and T18 shafts that are very hard to source from standard suppliers.
Understood, but the quoted parts won’t work without some serious work, and that probably needs to at least be noted in some way in the BOM.
I used ultra-low-profile sockets with standard square-pin pin headers.
Even with these, you’ll need to get rid of the plastic spacer strip on the pin header somehow, so there isn’t really a solution (that I’ know of) that will work without some degree of hacking.
I found the whole screen mounting thing by some way the most painful part of the whole assembly process, I have to say, and not just because of the header problems- the lack of space around the mounting holes in the display carrier board made it impossible to use standard hex standoffs as spacers between the display board and the bottom of the panel.
I don’t know what others have done here, but I ended up snipping one side off a stack of plastic M3 washers, and using those instead of the standoffs. It was a fiddly job cutting and fitting them, though.