It might be possible if you scrape alot of the Trench Digging code to the tool, also this would be useful I suppose, you could put down 2 2x2 bricks next to each other and click the brick while equip-ting the Welding Torch and then the other and it would combine into a 2x4 brick.
This would be useful if you've found something that maybe a bit spammy and can't change it without deleting like a roof or something, almost like Multi-tools, really.