"85 and 116 seem to bring with them the 8 minute freeze"

 

Then something else is wrong because I find FSX runs on only 1 LP without freezing so It can't be down to affinity masks.

...this happens a lot, folk try to arrange the sim around the addon  - instead we must arrange the addons around the sim.

How to go about this: Start with the best sim setup 116 or 85 - after that set the addons up so they do not ruin the performance....

First start with a fresh cfg file - no tweaks just AM=85. In the sim set for Unlimited, locked is very hard on even the most powerful systems. Use NI to set 1/2 refresh for fullscreen turn off all AA, and in the sim sliders mostly left, otherwise you could be flat-lining somewhere and no amount of fiddling will prove anything to testing.

From this point you should have good performance. Now bring in your addons, keep the performance in it don't be enticed to turn up sliders or enable AA until you have setup your stuff.