The thing is I have had no proper time to at least review the paths access tags besides vehicle paths where we have LS22 lg3 law applicable. Hence why there are so many paths with inconsistent and even incorrect access tags even in my most knowledgable district in Tallinn - the Mustamäe district. So its not anymore such a mystery on why crossing has more access than the paths it connects to. Its simply that the access tags of the paths or vice versa, have not been set up properly for whatever reason, in my case having only two hands instead of four.

But there are other access tags also. For an instance dismount tag. We could use dismount tag too as it gives specifically for cyclers on non-signed crossings a right of way as a pedestrian. Basically any crossing that is simple zebra, could use this tag instead of yes or designated. Even more so... In a lot of places I have seen cycling and pedestrian path road sign that ends cycling and pedestrian path right before the crossing, rendering the crossing that way to simple zebra where cycler has no right of way to cycle over while dismount would give a right of way as a pedestrian. How we should then mark such crossings? Dismount? Yes? Designated?

For crossings that have road markings such as simple zebra and cycling and pedestrian path has ended with a proper ending sign right before crossing I propose Foot=yes, bicycle=dismount.

For crossings where cycling and pedestrian path has not been ended with proper sign right before crossing and the road markings are simple zebra, I propose Foot=yes, bicycle=designated.

For crossings where the cycling and pedestrian path has not been ended with proper sign before the crossing AND the road markings are not zebra but some other road marking or combination of markings with zebra, I propose Foot=yes, bicycle=yes.

But this is all regarding the signed aka marked crossings.
Unmarked crossings are a bit more tricky one in this case so we should at least get some simple rules for mapping marked crossings first as was the initial idea of your original post. First things first as they say it :D 