It's probably working, just not very well. Do a "show drmomemtum" in the console to see whether it's actually changing values. As it is, it's very difficult to get it to increase and actually maintain it high enough for a critical. I've only pulled it off twice, and that was against very tough bosses in extended fights.

Anyway, the bad news is this thread is getting lock soon due to hitting the post limit. The good news is all the issues/solutions are probably in this thread somewhere, just have to do some reading. Maybe Klaus will start a new one.

Yeah, I did a lot more toying around with it since I made that post. Momentum IS working, it's just stupid difficult to get any kind of real momentum going. Is there any kind of edit I could do to the DeadlyReflex.ini that would make momentum come a bit easier?

Yes, search for scc.momemtumincreasemult. The lines after that as well all relates to momentum, you can try experimenting with those. Far as I know there's no recommended settings.