Getting ready to put it to the K & M sharpener. What do y’all think 40 degrees inclusive for the angle?
Well treated 440C will take a much thinner edge. Otter's blades have a good heat treat.
I'd go 20 to 25 inclusive. The keener the edge the longer the working edge lasts.
That's the angle I take my 440A/440C/420HC/1095/5160/T10 and other quote-unquote "simple" steels to.
Back in the day, Case, Ulster, Imperial, Old Timer, Camillus, Western, and others recommended 10 to 15 degrees per side (20 to 30 degrees inclusive.) I've had no chipped edges in over 60 years.

My few S30V/CPM154 and D2 are at 28 to 30 degrees inclusive.
For some reason the "Modern" steels have a recommended "sharpening" angle of 15 to 30 degrees (or even more obtuse) per side.
I had one knife with 1.114 KRUPP blades. The manufacturer recommended sharpening to 70° inclusive!
I'm sorry, but 70° inclusive is
not sharp. Can't even whittle a point on a pencil at that angle.
I use the "thumbnail test" to check the sharpness.
thumb flat on the table/bench, knife held vertical, with
just enough force to keep it vertical and from falling over.
Slowly tilt thumb. If the thumb reaches 75° (or greater) before the blade slips, the blade is sharp.
Most of mine reach 80° before it slips. A few reach 85° (+/-1°).
Cutting paper/news print dulls the blade.