I wish! I can just manage that when I am really fit (and no asthma) with 26:40 which is quite a bigger ratio than 1:1. In normal times I need 26:46.There is no need for a 11-50 cassette. Don´t forget the Quest has 3 chainrings in the front even in the standard configuration you have a ratio of 1:1 enough to climb hils up to 15%
For the VM I expect a higher range of gears is needed in the areas with some mountains.ride the 11-28 57 was a bit to hard to get going .
Not on all Quests. The older Quests have a smaller gear cover and I think also a different (shorter) derailleur. Mine was 404 and couldn't be fitted with a 12-speed for this reason.