While there is a long trail of tears around no-circlip problems, I've yet to come across an archive of owners complaining that the 0.05mm axial play clearance of the gearbox shafts is causing people's RTW trips to come to a halt. Perhaps maybe they got that one right.
Besides, given the shim sizes they made available (when they were all available), the 0.05mm figure obviously has some play in it as well. A little more; a little less. Probably OK. I'm shooting for a fit in the 0.05mm to 0.10mm range since shims are not available in an infinity of sizes.
1974 R90/6 w/1050 kit
'91 Bill Holland Steel w/Dura Ace