Mast length effect on roll stability

I am running a 71cm mast on a core 1250cm2 wing with 70cm span. I find the roll stability a little twitchy for me but I can ride for several km without too much trouble.

I have a 91cm mast I could adapt. Would that be better or worse for roll stability. My initial feeling was that it would be worse but possibly with more mast in the water it could calm things down. Also better for rough water.

Thanks for any advice.


PS what an amazing sport!