You can find an sga extractor and a rgd converter on the internet. The sga extractor gives you rgds when you apply it to the CoH2 data files, and the rgd converter produces xml. However, the rgd converter I found produces very incomplete xml that is not usable.

The rgds indicate that some of the ability names have changed, e.g. the german strategic_bombing ability is now strategic_bombing_mp. I tried making a new ability with the same name for a mod, but it didn't replace the missing one when I built it.

I was, however, able to disable it with a script. There are function calls to change manpower and munition costs, but not a documented one for changing fuel costs.