I recently connected an Ensoniq ESQ1 to the app "SysEx Librarian". The intent was to establish a link that would enable a MacBook Pro to send and receive program patch contents, sequences, etc. between the two. Upon first use, the Mac apparently sent a stream that overloaded the ESQ1's OS. The effect was so bad that it rendered the ESQ1 useless. The program banks were corrupted and the next powerup sequences would not go past the sign-on message. Doing a "hard reset" as directed by the Ensoniq official manuals accomplished nothing. I finally had to take it to a repair shop so that their tech could safely shunt the battery to internal ground for a few moments, effectively resetting the entire internals, including the OS. This got the keyboard back into a stable condition and now it is working fine again. (The tech did not have any advice about how to prevent this from happening again.)

The SysEx app has a long and well-proven history. I find it rather strange that a simple MIDI data stream intended for storage only would somehow get past the patches and into the OS of the instrument. For now, I am refraining from any use of the app except for possibly other keyboards, drum machines, etc., that have more fixed-style patches. Hopefully I can gain a better working knowledge of the app. The app's manuals only offer vague suggestions about delay factors; essentially, "shooting in the dark". In case anyone knows how to configure the app's delay factors better than its documentation suggests, comment is invited.