I prefer Bullseye in the .32.
However, you'll get higher velocities with 231.
I'd try starting at 1.8 of #231 and work up to where you get smooth consistent functioning and call it good. Lyman gives 2.5gr as max and most accurate in Manual #48.
Most of the 231 I've shot through the .32 has been with 60gr JHP's. I use 2.9gr for ~1,000fps. This closely matches the Fiocchi factory load velocity, but the 60gr Hornady XTP is a vastly superior bullet. Ditto the Speer GoldDot.
2.7gr is more accurate and less stressful on the gun.
My preferred load with my 78gr Lyman RN is 2.0gr o Bullseye with the KelTec.
With the Berreta TomCat, I used 1.8gr. The recoil operated action of the KelTec is "happier" with 2.0.
BTW; my KelTec shoots to POI/POA at ~7yds.
A very useful little pistol!
I work-out by walking a woodland trail along a large impoundment near my house and carry the KelTec in my pocket daily.
edited to add:
I "tagged" my ancient Chrony (before the F1; still had cardboard diffusers) with gas-checks from some .338ME loads I was working with. I replaced it with the "Caldwell Ballistic Chronograph". I'm very pleased with it. It sets up quick, and is very sensitive on bullet passage and much, much less sensitive to low light and low angles of light. I bought mine about a year ago when they were less than $80. They've gone up considerably the last time I saw one advertised.