I made sure I zoomed in a place that I've never been before (or at least in the last n years). Pure Maps does get significantly slower when it's pulling from osm scout server so you can tell when it's cache and when it's offline maps.
OK - I gave this a go (with currentposition=accurate GPS location). You can walk from London to the peak district in just under 52 hours!
Just tried an offline search of the "lake district" (since summer is here and why not try a place in the UK where it always rains) - but I got no results back, and an error in osm scout server: Valhalla: (stat): tiles.tar no such file or directory. This could be, however, a problem with my filesystem. I'll check it and report back.
A more conservative UK post code search works ok.
EDIT: search for "lake district" works without me doing anything, so it's probably an issue with the fact that the maps are in an SD card, which is also encrypted. Maybe something times out in the stack. This is working as usual in general.