Ok, it makes sense. In your opinion, how do the other websites deal with this risk?
Anyway, thanks for your wonderful service

Actually, the foot-hiking profile on openrouteservice.org works fine https://maps.openrouteservice.org/directions?n1=46.336821&n2=10.513798&n3=17&a=46.337358,10.514635,46.336306,10.51294&b=2b&c=0&k1=en-US&k2=km Same for graphhopper https://graphhopper.com/maps/?point=46.3...

Pedestrian routing fails around Bocchetta dei Tre Signori
openrouteservice and graphhopper also both fail similarly.
Osmand works
My only suspect is sac_scale=demanding_alpine_hiking but I was not able to find another similarly tagged way to test my idea.