In the topic where I presented this new walling method (see here), this was also suggested as part of the solution, more precisely to perform this walling selection using similar inputs as for the gate rotation.
You can test it in this tool: https://codepen.io/nvandernoot/full/MWaGMbL
I am already very happy to see it implemented in the game. Maybe this could also be added in a future update if many people are interested. 
Here you can see how fast (and easily) we can wall the base with this additional trick:
