This does not apply to difficult projects like emulators.
E.g. suyu, a yuzu fork, does not seem to get much development. Most of the changes are build or documentation related. [1]
Those emulators will work fine for the currently supported games, but without new competent people (trying to stay anonymous), I don’t see how these emulators will improve.
Why LVM + BTRFS instead of only using btrfs? Unless you need RAID 5/6, which doesn’t work well on btrfs.