After a lot of work to get to the core of my issue (MPC randomly freezing, see
viewtopic.php?f=4&t=177971#p1685225), it turns out that disconnecting the MIDI IN connection coming from my Prophet 12 fixes it. The Prophet 12 itself is the first of three MIDI devices connected to MIDI OUT C, and although Soft Thru is off on the MPC, whatever the P12 sometimes sends backs, it's no good for the 3K. Go figure …
As my 3K literally is the MIDI Production Center it was designed to be, this find may be of interest to those who work with similar setups. That being said, it should be noted that "Copy Events" copies events albeit without any applied Timing Correct settings (Swing&Shift).
I know why my topic has been prematurely locked. As we all know how topics mentioning a certain aspect end, it's futile to comment this. No offence taken.