Thanks for the suggestion. Currently this isn't one of the available filters, but routes you have done (excl projects) should be marked with green background, and so the not-yet-done routes should be easy to see. In the topos in the app, the routes you have done have dot that represents the ascent style next to them in the topo view.
When checking for climbs you still didnt do f.e. at your home crag it can be useful to provide a filter option based on the crag or sector that only shows routes/climbs you still havent logged (rp, os, flash) yet. (Personally I wouldnt include "projects" into this filter)
Is this already possible?