I never knew any of the "cheats" existed on the old ACE machines - many a cigarette smoke-infused spanking was had in the arcades of Sheffield, back in the day...
Unfortunately yes, one of the most fuckable families of machines ever. Like you, I had no idea back in the day, the drubbings I had handed to me by those things....
ACE were so bad for this stuff that one of their coders was actually sent to prison for deliberately coding shit into his machines, selling the details to a select few, and also doing the machines himself with the bent shit he'd coded into them!
We've talked about it over at Desert Island Fruits at some length, and those who know a bit about coding (we can get into the code pretty well using the emulator and its debugger features, as well as decompiling the ROMS) are left with no doubt whatsoever that most of the nonsense on ACE machines was purposely coded in for the purposes of corruption, rather than oversights or mistakes.