Well, the T/C Dimension is a bolt rifle so within one of your parameter options, and has been brought up, but the canti-levered mount that goes with the barrel has to "lock into" the rear of the scope mount which stays with the receiver (unlike the Contender and Encore series's, and the NEF Handi Rifle, and Rossi Rifle, and CVA, and...); therefore I am skeptical that a Dimension setup will actually hold zero - can anyone confirm or deny? Plus the Dimension can only be had with a butt ugly synthetic stock - no wood.
Yeah, AR15 and AR10 pattern rigs can swap uppers in 20 seconds flat, and they will hold zero if you have pretty tight pins, and probably even if you don't - the play in the upper and lower, if any, doesn't always affect accuracy, but can.
There are many other so-called "multi-caliber" rifles where the *barrel* swaps out pretty fast and easy (e.g. the Desert Tactical SRS rifle, the Sako mentioned immediately above, several others), but it's a siren song, IMO, and makes no sense to me because you have to "re-zero all over again" to paraphrase Yogi Berra.
I'm not a fan of switching anything. I want ALL of my rifles to be "grab and go" - complete with a receiver & stock dedicated to and complimentary to the barrel or upper, and dedicated to a very specific bullet and load, and left zeroed for load and not changed. One I settle on a load and a scope, which might take years, but it does happen, I don't want to change anything, and I want it to be ready to go at a moment's notice, whether for hunting or self-defense. I view most of these switch calibers as useless gimmicks.
Yes, I have a T/C Contender, but it's dedicated to one and only one barrel.
YMMV. ARs are pretty fast and easy to swap, and I'd be the *least* averse to having multiple uppers and one lower with an AR system, relative to others - but I didn't even do that when I had ARs.