I see that nobody replied to your post, so I'll TRY to help a little. I really don't know much about this hoya except that the leaves are similar to kentiana and string bean hoya. I would think to treat it the same exact way you treat your carnosa. I would probably repot now because the roots should be IN something, not just out in open air. Also, pumice alone is really difficult to work with...it has no nutrients and you'd have to water quite frequently. I never had a problem repotting a plant before it had a chance to get used to my house.
Good luck,
Gabi

I defer to Christina.

-Leon

Here is a link that might be useful: Christina info on pauciflora

Thanks for your input Gabi & Leon.

I will repot it now rather than wait. I found Christinas info before posting here, and it was her experience with it that got me asking all the questions!
Fingers and toes crossed that it doesn't drop all it's leaves!

Sarah