Certain abilities using Quick Cast will have the input not registered and buffered if the quick cast ability is pressed and released immediately after another ability during the window when your abilities are greyed out, will call it the Global Cooldown (GCD). The most obvious and hindering example I've noticed is Doorman doing Luggage Cart and then immediately trying to quick cast Doorway. If you do it too fast, the door never comes out because the input isn't being registered during the GCD. When using instant cast Doorway, the door input is buffered and placed as expected if the key is pressed during the GCD.
Another example is Vyper Screwjab Dagger into Quick Cast Lethal Venom, with the same exact behavior as above.
I assume this is due to the way Quick Cast puts you into "confirm" state on key press, and activates on key release. But because the GCD is active, you can't enter the "confirm" state, so you can't cast or buffer the ability at all. I would expect that if you can buffer instant cast abilities during the GCD, you should be able to buffer the press + release of a quick cast ability in a similar way.
For Doorman specifically, this difference in behavior makes it feel like you have to sacrifice something very important to the Doorway ability depending on which cast mode you use. With instant cast, your combo is 100% guaranteed to work and buffer the door after the cart, but you completely sacrifice being able to see your ability range from your existing first door. With quick cast, you can see your range, but you sacrifice the consistency of the buffer.
If this is considered expected behavior for quick cast abilities being pressed during the GCD, I would then suggest adding some sort of alt key to allow you to see the ability range/confirm state for an ability when using Instant Cast. Generally I would say that sacrificing that is expected when using instant cast, but not having that capability to just check if you're within range of your first door at all without casting Doorway feels bad when using instant cast.
Another example is Vyper Screwjab Dagger into Quick Cast Lethal Venom, with the same exact behavior as above.
I assume this is due to the way Quick Cast puts you into "confirm" state on key press, and activates on key release. But because the GCD is active, you can't enter the "confirm" state, so you can't cast or buffer the ability at all. I would expect that if you can buffer instant cast abilities during the GCD, you should be able to buffer the press + release of a quick cast ability in a similar way.
For Doorman specifically, this difference in behavior makes it feel like you have to sacrifice something very important to the Doorway ability depending on which cast mode you use. With instant cast, your combo is 100% guaranteed to work and buffer the door after the cart, but you completely sacrifice being able to see your ability range from your existing first door. With quick cast, you can see your range, but you sacrifice the consistency of the buffer.
If this is considered expected behavior for quick cast abilities being pressed during the GCD, I would then suggest adding some sort of alt key to allow you to see the ability range/confirm state for an ability when using Instant Cast. Generally I would say that sacrificing that is expected when using instant cast, but not having that capability to just check if you're within range of your first door at all without casting Doorway feels bad when using instant cast.