[embee]

Yes, std air gap (from memory 106mm, may be wrong on that).

Mixing oil unfortunately isn't a perfectly linear business, but you're not likely to be far out if you assume a simple proportional relationship, so 50/50 would be about right I suspect.

With a lower VI it's going to be thicker than the Pro RSF when cold, so aiming at 50/50 would probably be in the right general direction I suspect.

Since you already have the oil, why not just give it a try. Ultimately it's going to be suck it and see, it might turn out just right for you. If not then you know where to go next, at least with changing fork oil it doesn't break the bank.