Wondering how people dry their ‘erb after running it for ice-water hashish?

Reason I ask, is I’m not a grower so material cost is always a factor. I use trim and buds from growers, and after mechanically separating the cream of the resin I would like to know the most effective way to dry the material in order to process it for BHO to make edibles from the remaining cannabinoids in the trichomes stalks and other non-glandular resin.

I have so far been squeezing as much water out as possible, then spreading as thinly as possible on a baking tray and putting in the oven on fan-bake at 30-40C for 5-6 hours until it is 80-90% dry then air drying the remainder before freezing to re-process.

When decarboxylating some hash oil I ran with butane yesterday, it only bubbled for 5-10mins at 120C rather than 25-30mins indicating that I had mostly decarbed in the re-drying process. It made the hash oil very oily and less viscous, resulting in a massive nuisance to collect up (and unsure what effects will be like - will I have degraded lots of THC-A into CBN?)

Any advice or tips appreciated!