Another quick update.
After driving the car around a bit more, it's clear that exhaust is a problem. It's taken half a dozen hits now, the clamp is not looking great, and the flexy is not going to last long. The exhaust has also been pushed up into the floor of the body to leave some small dents.
This photo is an attempt to show how low this front section sits.
The clamp:
So, I've come up with plan to modify the front section of the system to tuck it further up into the car:
I'll cut off the main V band clamp and flexy.
Add a second small flexy to the "Y" merge section.
Add regular 2 bolt flange further back, just before the resonator.
Then connect the ends back together with a slightly ovalized length of pipe,
I already made a start on merge section.
Hoping to make some more progress this weekend.