I tiller all my bows outside under a shed,I do mine in stages and yes if it is humid or raining I will keep them in a hot box, or heater/ac duct in between sessions. I floor tiller then let rest,then to first brace,rest then on to 10 or 12 and rest and so on utill I am finished. I stay away from the last 6 or 8 inches of the bow and the fads out a few inches until I start getting close,say 20 inches or so.If you get the fads bending early is is very easy to get set there and it will really show up bad at the tips,a little set in the fads will show worse than set most anywhere else. Remember there is a difference in set and string follow.
so adding more reflex isn't always the answer.
Also my long string tillering is done with a very tight long string,I think at least for me it gives me a much better view of what is going on in the bend.
I also try and get it to short brace as soon as possiable.
Pappy