80 is fine, figure it varies a bit
I have been doing this for three seasons now and started incubating at 75 which I got from one of the original PF teks. When I went up to mid eighties, incubation went much faster and there were no problems (so far).
You obviously are more experienced. What is the problem with mid eighties? Does that have a negative effect on more cubensis strains than others?
I am now only at the point where I still shoot up jars with a syringe, but do not fruit the cakes. Instead I use the casing method, but nothing about the incubation has changed.
P.S. This site is very nice. For a while there I was afraid all there was was the Shroomery. A good site fror cultivation info, but the forums are hellish...