Apply Modifiers to Collections, Select Collections in Modifiers

1] Imagine you want to make an animation of your building growing. You need to apply every object's modifiers, add a boolean modifier, select an object, Ctrl+L -> Modifiers.
There are 2 problems with this method:
1.1 You need to manually select each object and manually apply every modifier, since there's no "Apply modifiers" operation in blender for selected objects.
1.2 It is destructive. You either lose all your modifier data or need to duplicate all objects to keep it. What if you have limited RAM on your system and a lot of geometry?
2] Imagine you have a collection of walls. You want to boolean all the window and door holes. You need to add N boolean modifiers where N is number of your holes. Holes are stored in another collection.
Now consider this scenario:
2.1 Select your walls collection
2.2 Add boolean modifier to the collection
2.3 Choose Difference and your collection of holes.
Done.