I think a separation (just living separately) as opposed to a legal separation may be effective for both of us (unless we see that there is too much conflict).
I agree that it may be effective, but why would/could there be more conflict? If anything, it would juxtapose the two lifestyles quite well. And point out how hard co-parenting and child exchange (even with older children) REALLY is!
Me: 43 XW: 43 T15 M14 D21, SS15, S11, D8 BD: 8/6 EA / possible PA discovered 9/29 D final 10/20