Whenever I have the 'Instant Request' personal cheat enabled it drops my FPS/UPS from 60.0 to ~45, and it's only getting worse as I expand beyond Vulcanus.

I've been able to confirm that having multiple Logistics Groups enabled simultaneously for personal logistics seems to cause this issue for the Instant Request cheat. Disabling personal logistics entirely or disabling all but one group returns me to 60 FPS/UPS. My first logistics group has around 70 request items in it, and the second group has about 15/20. Something about having multiple enabled groups causes issues I guess.

Just an update to say I've discovered this does still occur even with just one personal logistics group enabled if you have enough items in it (I want to say 60/70+ on my machine?)

Thanks for your report!
I've looked at the issue and I'm not 100% sure how to solve it. Fact is that I have to iterate over the whole list of requests and check if every single request is fulfilled like in there's already enough items of this kind in the inventory.
Not sure yet how I can accelerate this process, but I will take another look

So, I've changed a few things around and I'm getting better numbers now.
I've configured around 70 item requests in my game and compared to the current version of the mod (10ms/tick) I'm getting a 10x decrease in CPU time now (0.9 ms/tick) which looks quite promising I would say :D
I will polish and test around a bit more and release it later this evening.

Thank you for your patience! <3

I'm definitely getting much better performance now, thank you very much! <3