FSU several millions
Canon several millions
Olympus made oodles small rfdr
Cosina only much smaller numbers
very rare to see one in use...
DSLR enormous numbers compared with rfdr yes
Cosina equipment is comparable in every way with other Ja manufacturers indeed as a 2nd tier supplier they may have made your Nikon or Olympus camera.
And for example Leicas have had significant problems with tolerances and won't take kindly to shock.
The last time I dropped a gbag the meter survived a Weston but the Leica rfdr way off.