So if you 'C'opied a room containing an FFC with argument d0=51, and then decided to Paste 'S'pec.->Freeform Combos in another room, the pasted FFCs would still have arguments of 0.
Spec. Pasting Freeform Combos doesn't paste their arguments
Wait what? You can paste FFCs??
You mean you haven't seen the "Paste Spec." menu option? It's in the Edit menu, below "Adv. Paste" but above "Delete"!
Fixed in the next build.