Foreign SYSEX is generally harmless (in that it won't overwrite the Mini's system data with junk from another synth) but a crash or freeze does not surprise me.
The MiniBrute is not (and cannot be used as) a USB MIDI interface. I've found that most gear that does not have a dedicated THRU jack won't pass SYSEX. Even some that have THRU won't do it.
Get a nice $10 USB to MIDI cable to go with your million dollar polysynth.