What happens if I upgrade to the Hobbyist version of MapHub for a year, save maps using a Thunderforest Base Map, and then after the year is up return to the Free version? Will the Thunderforest maps remain saved or will they be converted to one of the free MapHub maps? (In that case, which map?)
You won’t be able to save the maps on the Free version, you’ll receive a warning about it.
My main concern is what happens to the premium maps that were saved when the Hobbyist version was active. Will, for example, Thunderforest maps remain saved and available or will they be downgraded to one of the free maps?
They’ll be available in a read-only way.
But if a lot of premium maps have already been saved, do they remain saved (and thus visible to users) or do they perhaps revert back to one of the “legacy” maps if downgrading to the free version of MapHub?
They remain saved.