It's possible to use midi note to modulate any parameter.
See part "4.4 Note Midi Scaling"
http://ixox.fr/preenfm2/preenfm/synth-edit-mode/But if you expect to use the exact frequency of the note and set the the Low pass frequency, it will require some adjustment.
Glide 11 and 12 have been added recently for slow glide. You need slower than that ?
You may think about using any LFO or env to the matrix target "o*Fq".
"o*Fq" ajust all operator frequency and make a global frequency shift.
If you manage to have the firmware compiling, i can guide you so that you can add what you want.
Yes Filter param2 could be modulated . It was not for performance reason as some of the filter requires lots of calcul when you change this value.
Modulating the filter itself or the algo, can only produce audio clicks and bad sounds.
You can still modulate them with external midi CC though if you really want to give a try.