Please add option in map settings to allow bind/anchor theme to map if user want it. When switchich current map to such configured map it is switched automatically also theme.
Theme selectable linked to map
if i change type of vector map, used theme is last selected.
user selectable theme fit to map, so user has always his favorite theme to selected map
Locus Germany map > theme "Road"
Locus Badenwurttemberg map > theme "Elevate"
OAM map > theme "openandromaps_cycle"
FZK map > theme "fzk-outdoor-contrast"