Wow. Totally missed that. Since I didn't see that section in the samples I looked at, I completely misinterpreted the instructions. Sure enough, restoring the original DT_INTS-14.bas and re-compiling with the 16F1825 was successful. Tried the same thing with other code on a 12F683 and it told me what to uncomment.

And guess what - reverting to the original DT_INTS-14.bas resolves the problem. No more runaway motor, no matter how many times I reprogram the chip. Sigh. The architect of my doom ... is me.