oldschooljoe, certainly not. VSF format is "Vice Snapshot File" and opening a snapshot, with a different emulator type, than the one, it was taken on, how is that supposed to work? Especially, when loading a snapshot in the most cases even don't work on later versions of the same emulator. Denise snapshots can't be opened in VICE or HOXS either, so unfortunately, this will not work, because they are all different file types.
You could maybe try, to load such a vsf-snapshot in that VICE version, it was made off and when the game starts, then freeze it with a freezer-modul and see, if this works? To try this out, you must turn off "Reset on cart change" in the VICE menue first, before you insert the modul (otherwise the snapshot is gone again), but even then, i am not sure, if this will work, because the question is, if the freezer-function will work, when a modul is inserted without a Reset? But it's worth a try anyway. If the freezing itself works, then the saved freeze-file can be used in all emulators of course.
Maybe that's one of the reasons why C64 Endings Website got abandoned.
We need to come up with New C64 Endings and with Newer Ending Modules that works on all emulators.