A 17,000 hour pilot either can fly a certified GA aircraft without a checkout, or should not be providing flying instruction in it. If that pilot
needs a checkout from another pilot, to fly it safely, they are not ready to mentor someone else in the following hour of their flying in that type. These planes are not that complicated!
If the type is exotic, and they need a checkout to fly it (and I can think of a couple of types: SM1019, Lake Amphibian, Cessna on amphib floats) then they are not ready to provide you training in it, they'll need so more training themselves first - and probably the insurer will insist on it.
Otherwise, if we're talking a PA-28 series, 172 Hawk XP/RG, or 182, just go fly the plane, it's darned near impossible to get propeller management dangerously wrong.
I'm not against checkouts, to the contrary, but I would not like pilots to think that these common (Cessna/Piper) fire breathers are going to challenge a 17,000 hour pilot. There have been a number of types I have flown where after I have checked myself out I have gone on to check out the new owner or pilot next, never a problem (though I concede, the least relaxing was the Piper Tomahawk, I approached that a little too casually
. Good 'plane, but training or briefing wise).
I will qualify the foregoing to say that if the variable pitch prop checkout is for a reversing propeller, that's a different story, and proper training is a must for that.