i resume, this is a merged map of 2 lines, a copy of a fan made route (made by dtg), so install this one or the original is the same just one is needed (both require albula line and bernina pass routes add ons), that's all. none have scenarios included for now, me i'm working on scenarios for this route, i don't think dtg work on it for their version of this route

no need two times... just need this one and the required dlc... (same rquirements for the original one anyway) the original merged route is without scenarios anyway, just need to install the version who have scenarios, for now... none of them lol anyway this merged map do not depend of the original one, it's stansalone, so don't need to install 2 tilmes, i don't understand what you mean

So the installation of the route has to be made two times. Hmmm...

i know, and yes i will do scenario, but i never work on the source object, i always work for custom scenarios, on a copy of the road, that's just what it is, the scenarios will now come i'm working on it

This merged line exists allready.
Better create new sceneries there...