Hi julcnx,
thanks for all your contributions to OSM! Especially the the Strava heatmap plugin for iD is very useful.

You're using "?" as the value for some keys, for example in  https://www.openstreetmap.org/way/696211212 which currently has "mtb:scale=?", "sac_scale=?" and "smoothness=?".

If we don't know the value, it's best to just leave the tag empty. That way, someone can look for e.g. "roads that don't have any surface info" and find those to survey them. If they have an unsupported value like "?", those won't show up in the search, e.g. in Overpass.

My suggestion would be to remove any tag that has "?" as the value, but maybe you have some workflow set up to work with this, so I wanted to check with you first.

All the best and happy mapping,
Paul