Safe to use M5 threaded Handles with 10-32 Head?

Looking for opinions on whether it is safe to use M5 threaded Handles with 10-32 Head.
Recently picked up this beautiful Karve razor with a Stando Suomi handle.

I am aware that the handle has M5 thead but the Karve top cap uses 10-32.
Is there possible damage to either handle or top cap threads if used regularly together?

Considering the amount of force you're likely to apply while shaving you'll be fine. The major issue would be in something like a high pressure mechanical system the very slight difference in the thread pattern would cause instability. As long as you're not going to be tightening the handle with a wrench you're good.

I would suggest making sure you have a plastic washer to make sure any slight wiggle doesn't cause scratches.

If the thread patterns were reversed you would risk stripping the threads and it would be a very tight fit, but the way you say it is will be very slightly loose. You may not even be able to notice.