I read your post a couple days ago. That looks nice and clean, did you have those ceramic coated?
You made me think about a Y under the cab, then going single out is my best move.
One of those times of, I couldn’t see the forest because of the trees. The thought of cutting that cross member is gone.

I’m running small catalytic converters and their under the cab.
Oregon, these old trucks still have to pass DEQ, so the first time I made a slip on with spring clips a dual to single tail pipe so they wouldn’t have to crawl under the truck and reveal it’s not stock.
(It’s a closed hood inspection and just needs to blow 86 emissions standards, so I play it safe.)
Deflated with it on I can lay (my hack job) exhaust pipe.