This is a feature of some game engines which allow people to use arbitrary keys (or combinations) as modifier keys. Which allow for less motion of the hand over the keyboard, by simply being able to hit the same keys (with some modifiers) quickly.
You would need an N-key-rollover keyboard to be able to do this, at least in the general case. Baseline keyboards do not register overlapping keypresses correctly, unless you are using the ordinary modifier keys.
Sure, but a lot of gaming hardware supports this, and it's a hardware issue. If one is customizing their editor to the point of using arbitrary modifier keys, they will probably be willing to buy a custom keyboard.
Also while on the subject 8 key rollover, which is pretty common, is probably more than enough.
I never knew about this. My laptop seems to have 8-key rollover for most (?) sequences that would be natural for your hands, but drops as low as 2-key for unlikely combinations. Any idea what's going on?
