What version of FOMM are you using? TTW specifies using 0.14.11.9.
Mod limit really does seem to vary from person to person - I've had a load order in the 130s run with no issue, but I also didn't have a lot of BSAs loaded. It's weird, but that has made a difference for me. It's probably best just to keep your limit as low as possible through careful mod selection and smart mod merging.
Extremely extreme extremophile.