As of the December 10th update of the 088 Beta (64-bit), the Primitive SOP is now causing significant (9 fps) performance problems. The two problematic instances of in the project both use expressions extensively. The same project ran in the previous November 7th build without any significant performance issues (~35 fps).
LinearChaosB.toe (470 KB)
I just discovered that if I switch off the audio input/output/processing, it works fine.
When I switch it back on, the performance issues start again.
I have determined that the problem is in the Pass Filter CHOP. Certain instances of it will output unusual data while in Band Pass mode. Switching them to another mode and then back seems to fix it temporarily. However after some time, it starts to output increasingly odd values.