Indeed. There were hidden patches, e.g. for Kick Off 2 by Anco (think some sneaky data over Index, really don't remember in detail). Cyclone patches boot loader, then writes a new one to 7x and continues there. Technically speaking this is cracking. On the fly...
Also Dragons Breath with SpeedLok on 79.1 would not work due to precomping. Also longtracks at >TRK50 were prone to break.
Still have the source code with Richard Aplin's comments.
It was ok for the time, but later Power Copy did a much better job. Within limits.