How about a different approach.
I am assuming that the bearing isn't moving. The basket is moving towards the crankcase.
Can you machine whatever is behind the clutch basket to fit a roller thrust washer to stop the basket (and gear) from moving inward. There is an existing flat surface fir the thrust bearing to ride against in the basket, so all it needs is enough space for the inner face and the bearing.
On older Suzukis there is a hardened washer either side of the equivalent to that bearing which is a long bronze bush. That is enough to stop things moving - most of the time because they act like thrust washers and contain/retain the basket laterally. When they changed to straight cut primary gears they kept those thrust washers.
A more involved solution could include a pair of back to back gears cut in different directions to eliminate side thrusts, but that would have to be the most complicated and expensive way to fix the issue.
It looks like AJR changed the clutch design when they came up with the straight cut primaries to include a roller bearing plus an inner thrust plate. It might be possible to use this part
https://ajrmotocicletas.es/epages/c...950-45ce-8ec9-2ca023feb311/Products/AJ5000074 with slight modification.