In the future, is it possible to load mods by passing in a list of manifest paths or a file containing a list of manifests through the command line?
such as Fabric for Minecraft

Hi! The SMAPI equivalent is --mods-path, which sets the folder path to scan for mods. This is used by some mod managers like Stardrop to toggle mods by just moving them into and out of its active mods folder. Is there something you need to do that can't be done with --mods-path?

I'm not necessarily opposed to the idea, if it's something many players or some mod managers would find useful. We'd need to rethink some of the surrounding logic though; e.g. the log parser assumes there's one mods folder, so that option would complicate troubleshooting a bit.

When different save files use different lists of mods, some shared mods are not wanted to be copied multiple times, especially for large-sized mods like SVE (exceeding 100mb); similarly, for such mods, moving them to deactivate them can be quite costly.
Of course, the current operation mode is not unusable, but I'm just inquiring about the possibility of further optimization.

To be honest, this requirement is actually rather niche. It's just that I have the habit of keeping historical versions, and the current loading method is quite troublesome when it comes to switching versions, so I just wanted to ask about it.
Moreover, for modpacks, when updating the versions of mods, it's not necessarily required to completely delete the entire mod folder. Instead, you only need to add the new versions and modify the loading list. Of course, this will lead to a waste of space, but it can also be regarded as an option.