i dont know ..
still seems low to me for a for a fairly freshly rebuilt windsor..
on re-build, I would expect at least 30 at idle.
FE's seems more common with lower pressure readings
more variable's like worn rocker assembly's for example,
but that can remedied with oil restricted oil port in head..
Ya, true dat.
Been a long time since I had a vehicle with a Windsor and an oil pressure gauge...
Used to have a 65 Mustang with a well worn 289 and if I recall... it ran maybe 10-12 psi at idle hot.
I still don't think 10 psi at hot idle is bad.
There is very little load on the engine at idle,
and he says the pressure comes up with rpm, as you would expect, so I still don't think it's a concern.
Now if the pressure stayed low, then I would worry.
Edit; for the record... I have had numerous "other brand" engines that had hot idle pressure ~ 10 psi and never a problem.
The 10 psi at hot idle seems normal to me.