By the looks of that one commit alone, I'd doubt it'd allow running second instances. At least on Linux, changing the config folder alone isn't enough to enable this. But there must be some combination of variables that might allow it, because using snap's parallel installation feature, you can do this. (This is presumably just setting up a load more of the XDG_* variables, not sure specifically which ones are required though)
It's experimental for a reason though. Here's some bad UI 
