Not always practical in a real match from a standing position. It's also easier to do iGDR from a standing position while doing a 2 step and only have to press 14B fast for the input.
i don't know if was posted or not, but i was testing some ways to do iGDR, and i think i got some way to get it easier in combos, the thing is, when you hit a launcher like 3B you inmediatly hold down(2), and when you want to do iGDR do the missing part (14 B), like this:
-3B > 8B+K~2 > 14B
I think is easier to land an iGDR this way, because in the 14 part, is easier to hit B and 4 at the same time.....test it guys, and tell me what you think.
testing I found that you can do 214 in a "paused" way like 2 > 1 > 4B, i will post a video ;)
-00:00....hold 2 version -00:14.....2 > 1 > 4B version