developers claim its unstable as forget but if no ones developing mods for it then what's the use
the primary reason for x64 being completely and utterly unsupported is this:
unity windows x64 build, as it stands, the version being used for KSP, is prone to crashes simply by being badly designed. it randomly tries to access invalid memory points even being x64, and with/without mods, WILL crash with 0 fault of KSP or the mod developers. as such, they're not even touching it. i'm using the ubuntu linux build of x64 with no issues, which i actually downloaded just for this.
I just played it for 30 minutes with the mod and I didn't have a single issue.
pls don't bring in a survivalist's fallacy.