I use the default 'F' key to couch/enter cover and I also experience the delay. The above did not help out at all.
I'm very tired and frustrated at getting killed due to huge latency spikes via the interface. I expect that if i were to hit the hot key for crouch and then the keybinding i have on for aim shot that i should start up my aim shot charge, instead what I experience is the ability that is on the toolbar for when i'm standing launches off then I crouch and then I have to wait a moment before I am able to act.
It is a very frustrating thing to experience while trying to pvp as a smuggler/gunslinger and I would like to see this addressed soon.