Question what is the URM folder when you download the incest patch for?
File, not folder.
When I am checking the different routes, to save time, I use URM to change the variables (e.g. changing Myriam from being DOM or SUB with Marc).
It can also be used to e.g. set a posterior if you want to have one of the cops as special person, or changing the level of submissiveness or love for anal of Myriam.
Also, in the latest versions, when there is a menu, it allows you to see the choices and choose even choices that would normally not be available.
Zorlun has done a good job of keeping that aspect relatively simple, by using for the kinks variable with a simple name, and to register the choices made by Myriam, variables with name like "CH4_dominated_the_boys" - the "relatively" is because there is a number of variables always growing as the game goes on, and it may end up being a long list if you want to monitor them on screen, but anyway it is easy to find them using the search of URM.
If you read the readme, the URM file is not strictly needed for the incest patch, it is an extra "bonus" I give for people who do not want to create their own - though of course people may want to customise it for themselves.
As indicated above, can be a way to see different paths without having to keep tons of saves - though especially for the variables that contain choices, and for the part of "choosing choices that would normally not be available" in the dialogues, you should at least try to understand what you are doing, before clicking around, lest you end up with an error screen (though you can always trying rolling back, since luckily Zorlun kept it active).
To use the URM configuration, you need to download URM - you can find it here on F95, just do a search in the fora.