I would advise verifying the
oil pressure with a known good mechanical gauge connected to the same spot as the sending unit for the dash gauge is connected.
Always verify that there is a real problem before you start looking for one. Otherwise you may find things to fix that might actually cause a real problem.
An incorrect gauge reading, in my opinion, is more likely than an engine problem that causes the
oil pressure to go high at both warm idle and at rpm.
The
oil pump pressure relief valve should not be open at warm idle, so you can rule that out.
A chunk of some broken part, such as roller lifters, should not get past the oil pump screen nor would it go through the pump without something bad, so a chunk of something blocking the oil system is not likely.
A spun bearing where the oil hole is blocked off can cause an increase in oil pressure and loss in power from friction increase. That friction increase and no oil flow in a rod bearing should have caused catastrophic failure rather quickly. I doubt this has happened. An FE cam bearing maybe, but that should have made something rattle somewhere up top. I still suspect the reading is false.