Hello there 
I hope this hasn’t been requested already: I couldn’t find anything similar with a quick search.
On a meatspace wet-erase mat, tokens, minis, dice, etc, won’t snap to the grid. If your system (or GM) allows for it, you can jam 3 creatures/characters side-by-side in a 10’ wide corridor, and display that simply by not giving a toss if the tokens or whatever are sitting on a line.
Roll20 uses the alt key for this; I’ve also noticed Owlbear Rodeo has a hybrid snapping system where it only snaps to the grid when moving over either the center of a cell or an intersection. Personally, I think I’d prefer the alt key approach as it’s less fiddly and more freeform, but that’s just me.
I hope this request survives the Brutal Focus! 
P.S. Being able to freely rotate larger formations of tokens as a single selection, ignoring the grid in the process, would also be very cool for wargaming shenanigans / mass combat—another thing that is kind of easier to do IRL. I realise that’s maybe more of a Select tool thing, but thought I’d mention it as the grid ignoring thing is still kinda relevant.
P.P.S. I notice there’s already an option with the Measure tool that ignores the grid. Perfect!!