I’ve got grid control on the mind too 
@kasselvania - I love these ideas. One of the complicating factors in regards to grid layout (maybe?) is that the list of available commands is quite high: 14, iirc. This would necessarily impose some restrictions, but I don’t think that’s a bad thing! Still stewing on a creative solution myself, and so I really appreciate any and all ideas.
I may be misunderstanding this, but, as currently designed, all commands affect both playheads simultaneously; in some cases, a command will sync them back up, and in others separate them to different regions within the buffer. As such, I don’t think there’d any need to swap between them? 
I was actually doing some sketching/thinking this morning, and I thought it could be interesting to create a bank of snapshots – each one would store a set of commands, making it easy to switch between a few of them:
In this layout, you select commands on the X axis, and the length of the command sequence would necessarily be 8. Curious to hear what people think!
This is all super preliminary, and I’d definitely be open to collaborating. If you want to shoot me a DM and brainstorm, @kasselvania, go for it!