aerobic definitely worse ... weightlifting can still cause you to crash though. general rules do apply but it seem to really depend on the illness state, which seem to vary between individuals over time. I had quite a lot of physical stamina in 2019 but I still had to be careful not to break into 'exercise', I could pedal my cousins bike around the street for example ( wouldn't have thought of doing that a couple years prior ) but I would feel ill immediately from doing it, and quickly stop.
I did a lot of stuff which was more arm muscles / upper body I guess like screwing things together, light sawing / filing, cutting things, lifting objects. Fishing ( depending on the weight of the rod it can take some physical effort especially if you gotta hold the rod in one hand while collecting the fish with the net in the other hand ).
I used an electric bike a lot, don't even have to pedal if its one you made yourself, its probably the best vehicle for me/cfs people who are reluctant to drive because of cognitive problems etc, Went offroad / cross country a lot... closest thing I am gonna get to exercise really. Maybe the adrenaline helps in some way. Picking the bike up to turn it around or lift over fences uses a lot of muscle strength ( but its not aerobic )or if you have to get off and push it through mud. I did use a mobility scooter for years but as I started going further and further distances it became too slow an inconvenient.
I lived in an environment with a lot of mould and bad air / stressful etc and that seemed changed the 'profile' of the disease, don't do half as much physical activity now. I started getting these intense sore throats, seem to crash easily and often my stomach starts to bloat up when I overdo it, so now kind of just waiting for some sort of medical intervention as I get the feeling that my disease isn't gonna improve much via pacing etc like it did before. Part of the problem I have is I seem to always want to push myself to do things that I would do when I was at a higher activity level.
I've lost so much muscle since it started in 2015, especially around the neck and shoulders. I've often wondered whether it even is possible to GAIN muscle with this condition. I guess it seems like a 'fools endeavour though' in a way... to do bodybuilding for the sake of it. You can definitely maximize the strength of the remaining muscle that you already have, by regular activity, but gaining a lot more bulk.... doubtful.