It's not unreasonable at all, but be conservative. I would suggest you'd want it in writing from the company, because if a civilian CP calls you on it at an interview you'd want to be able to refer him to the guidance.

Any mil CO/DO is not going to need to check those boxes to get an interview today anyway.

I don't know who BK is or what airline he works for, but the FAA doesn't consider 119 jobs to have military equivalents.

I believe he was talking about United, either way there is no reason for a military person to check the CP box. Most applications ask if you were chief of safety, Ops O, or CO. If not it will be in the duty description. If you are one of these your application will stand out.

In my experience...

There was no Chief Pilot designation or position on Active Duty (airlift world). However, in the Air Force Reserve, there was. It was an official position, and was recognized as such on your Duty History and OER. The CP duties included Hiring, liaison to airline CPs, advocating for the pilot group, low level discipline, and morale. If I were a Reservist, and had the title on my OER, I would feel comfortable checking the box.

I don’t know what an OER is but we definitely have CP’s in the ANG who put it on their OPR

One more time.
Unless you have something in writing from a potential employer no one gives a rats %^*+ what you called a position in the military. Chief Pilot and Director of Operations are FAR 119 designated positions and last time I checked the military does not fall under FAR 119. Heck, you can put Captain America in your OER for all I care, that doesn’t make you Captain America in the real world.
I’ve been a commander with UCMJ authority in charge of 150 people and 13 airframes. I wasn’t a CP then. I was a commander. I was a CP/DO when the FAA designated me as a CP/DO under FAR 119.
So unless there is something in writing from the people you are interviewing with leave it off.

You sir are correct! After getting hired at the airline, I later became a chief pilot in a reserve sq. Duties are about the same as at the airline. I think the Guard might have Chief pilots too, but not sure,

Where is that listed in FAR 119?
Or in a Military or Guard regulation, where is that position listed? I’m familiar with a commander, and XO, an operations officer, but a chief pilot?? What kind of UCMJ authority does a chief pilot have? Sounds like something Guard/Reserve people made up to help out fellow Guard/Reserve buddies getting hired at legacy carriers.

Which regulation covers the duties of a CP in the Guard and Reserves? I served active duty, Guard and Reserve but never remember seeing that position in any regulation. Granted, I was Army not Air Force, but I would think I would have seen a reference to such a position.
What kind of UCMJ authority was held by a “chief pilot” in the Guard/Reserve? Did they have operational control over flights like a CP under 119? As I wrote above, sounds like a made up position so Guard/Reserve buddies could check that block on applications. Not very honest if you ask me.

That could be, but if it's an official title in the military you would be safe claiming it, if you have it in writing.

Same for CP of a 61 flight school or 91 flight Dept.