Ok, got a Windows BSOD - unrelated to Fences - but since I had to reboot, I took the opportunity to install the update above. No difference - UNLESS I don't use Peek. I never paid much attention previously to whether I was using Peek or just revealing the icons via desktop click and launching from there. I suppose I've been using Peek all this time.
Via Peek - same old delay, every time.
Click on desktop to reveal hidden Fences, double click any program - instant launch.
Here's a demo - https://app.screencast.com/Kj3cDSUAINvzR
Also, to be clear, since I didn't do this in the video. I just finished repeatedly launching that app via desktop click then double-click. Launches fast every time. Then tried 5 times with peek, slow to launch EVERY time.