I test flew a CF with a P-60 in it a few years back!
It flew OK, nothing in the vertical to talk about, but once on the step (2 circuits pinned!) it flew OK. P-80SE is great, we still have a few CF on the original P80 and that comes off a 90m grass strip.
I would always fit the byepass, the original 2 prototypes (RIP) did not have byepasses and we flew one in Germany May2006 with a P-70 and the other with a P-120, for a laugh we swapped the P-70 for a P-160 on the Saturday night without telling anyone and although it had better vertical, it was no faster than the P-120. That's when I asked about a full bye pass and ended up with the first one which still has a 2005 P-120 in it. Though never tested I'm sure there is less drag on the full bypass and less chance of a fuselage fire.

Dw