This is quite thought provoking. I never thought in this manner.

Don't bother using collection. When I made one for personal use, the fucker downloaded some outdated version of the mod. I started using my download history to keep in check what I've downloaded and used vortex to handle the installation. Keeping bookmarks would be a better option.

In general, simply dropping the mods in the correct location installs the mod, but few mods (like in case of Cyberpunk 2077, Redmods) get compiled to show up as game files, which might complicated the proceduce but I think its possible.

I don't know what you mean by downloading one by one. Nexus does lets you download multiple mods at a time when done manually. When installing mods with Vortex, it downloads it, installs it, verifies it and looks for the next in the queue.

But if you are still keen to use more bandwidth, perhaps try using tor, see if Nexus allows it? I haven't checked on my end since I never really downloaded huge mods.

IIRC, Vortex can install manually downloaded mod files.

Note that mods are not piracy. Developers make toolkits to extend the longevity of the game.