I brewed my 2nd batch of this yesterday, and also used Belle Saison yeast (both times). Although I always rehydrate as per the instructions.
My suggestion is to let the wort temp free rise as it likes. Just cut power completely to your ferm chamber and let the wort dictate the temp. Last time, I pitched at 68°F, held there for about 18 hours (until I saw activity....which could have been sooner but I was at work), and then cut power to my chest freezer. Here's my notes on the temp thereafter:
At 26 hours, 72°F.
At 36 hours, 76°F.
At 48 hours, 78°F.
At 72 hours, 80°F, still bubbling nicely.
At 100 hours, 82°F, little signs of activity though nice krausen remains.
At 120 hours, 80°F.
After 2 weeks, pulled carboy and set at room temp for another 2 weeks, then dry hopped 2oz Mosaic for 5 days; cold crashed @ 34°F for 36 hours.
It turned out absolutely fantastic. One of the best beers I've brewed (top 5 for sure). Belle yeast brought it from 1.070 to 1.000 (9.1%), but you'd never know by drinking it.
Cheers.