Xavier,
currently the preenFM2(/3?) has 7 standard and 6 additional user-waveforms. The standard waveforms consist of all the usual "analogue"-type "basic"-waveforms (sine, triangle, square...) and some "special" ones allowing for different side-band spectra...
As FM-synthesis in fact is some sort of additive synthesis, it strongly benefits from some more "special" modulator waveforms allowing for better control about the number, position and strength of the harmonics in the generated sidebands.
I have no idea, however, if the PreenFM2 would have enough RAM left for this (I really wouldn't like to sacrifice the user-waveforms for that). But if there is enough RAM left for the stunt and if there is enough interest in this I would/could donate some specifically crafted waveforms in this regard.
best,
Stefan
PS: Why not using the already existing user-waveforms for that? Well, it would limit the ability to share the resulting patches...
