It's been a long-time, but I used to use Tinder quite a lot when travelling. I sometimes mentioned
MC, I sometimes didn't - what I can tell you is it definitely had an effect on whom I matched with. Overall, no-one I ever used cannabis around eventually ever cared much - but I'd say I had less opportunities when I mentioned
MC upfront.
That all said, some of the strongest/longest couples I know personally are where both people use
MC. If you're looking for someone whom can truly understand and accept your medication/usage, I'd definitely say mention it upfront.