Simon,
A lot depends on how localised and pronounced the reflex or deflex is, how strong the stave is now and how strong you want it to end up. If stringing the bow to a lowish brace height now is acheivable and won't overstrain the wood (go over final draw weight) then perhaps the best thing to do is do that now so you have a good idea of what you really have. It is very easy to end up whip tillered or underweight with too much floor tillering or tillering on a long string.I learnt this the hard way. With reflex it is easy to go to weak as the early brace strength is higher than normal. I think it works well to keep at or very near and never over desired poundage, working the wood to this weight well after every wood removal, working the draw length back, keeping good shape and within draw weight.
Yes, you would have to live with and and make allowance for a pronounced localised reflex or deflex. Keeping an eye on where any set is developing shows where the wood is being stressed too much and so wood needs taking off every where else. If you aim for spreading even stress over as much of the limb as possible you won't go far wrong.