I've not seen it mentioned in any of the other threads, but...
Triumph is extending their partnership with Arrow Exhaust on the TFC. That means it most likely already has high flow cats. Without a redesign in header AND cans, you're not getting a lot more hp by swapping them out.
The other side of that, the non TFC models will come with more restrictive exhaust, producing less power, and may not match the 2300cc.
*Edit* And another item, My '19 Street Triple has a high flow cat built directly into the header and a cat box underneath. If they continue that practice, it will require the header be changed to increase power