Clover upgrade fail "This package is incompatible with this version of macOS and may fail to install."

I'm trying to upgrade Clover to latest (v4380) from v4289 and keep getting "This package is incompatible with this version of macOS and may fail to install." (I'm on Sierra 10.12.6)

I tried installing anyway, but result was "Installation failed."

Also, during install, EFI was mounted, but appears as Volumes/ESP not EFI! Yet on desktop showed as "EFI". Disconcerting.

(I used "install to ESP" option; old mobo.)

Now I'm afraid to reboot; afraid that Clover/MacOS won't boot.

Help!