I tried that patch, and it only allowed you to float on the sprite for a second or two before sliding off, rather than working as a solid platform as per Keen 2 and 3.
There is also a patch used in Retrosis that makes icecubes continue to function and remain alive while offscreen. Using that, the bots work perfectly well as horizontal platforms.
Also I found the original thread for the patch I'm using:
viewtopic.php?t=1334
It uses existing Keen 2 code (I assume they had a custom library that was linked into each EXE), as opposed to my original impression that it was overwriting the freezing code in the Keen sprite collision switch. If it's just a hijack jump/call from the ice cube entry, it should be possbile to squeeze it into the bot collision code, with the side effect of it also applying to the tank bot.