Key chains/sequences: how to be agnostic to when the first key gets released?

[ckp95]

I am trying to set up a key chain / sequence where I can press right-ctrl then enter, and it will open a terminal. But it doesn't work quite the way I want. This is what I have:

Control_R; Return
  kitty

This works when my fingers do the following actions:

depress right-ctrl
release right-ctrl
depress enter
release enter

But it doesn't work when I don't release right-ctrl first, i.e. when I do:

depress right-ctrl
depress enter
release right-ctrl
release enter

or

depress right-ctrl
depress enter
release enter
release right-ctrl

I basically want it to not care whether I've released the right-ctrl key first, the same way that when you type "abc" in a text editor you can depress the b before releasing the a. In other words I want all three of these to work:

             time ----->

right-ctrl :    ▼    ▲ 
enter      :             ▼    ▲ 

right-ctrl :    ▼    ▲ 
enter      :       ▼    ▲ 


right-ctrl :    ▼           ▲ 
enter      :       ▼    ▲ 

It's annoying to have to slow down my fingers to make sure that the release of the first key happens before the depress of the second key. I want it to feel "fluid", if that makes sense. Is there a way to do this in sxhkd?