The big problem with these PTL's is that we can't often make them on return to PER as we were delay 30 - 60 minutes off STD due to the morning taxi slot times.
Now as an ATC if find that massively embarrassing, we've given someone an instruction and then made it impossible to comply!
The slot time process is flawed, as is the PTL - however what alternatives are being proposed? If your colleagues are rorting the system, then that is is an issue for you take up with them - not ATC.
I disagree. Its up to us to enforce them, or as I said, scrap it altogether.