I guess the question is how small could a 'jeep'carrier be in modern warfare?
Consider that the F-35B is STOL, carries a far more accurate bomb load half of that of a B-17 internally, retains air-to-air capability with that load, and does so in stealth mode, and can haul standoff cruise missiles for anti-ship and surface attacks, the potential is there with just a few planes to do what much larger wings did in WWII, only using stealth and guidance tech only dreamed of then.
Some sort of CAP would be needed for defense, upping the number of aircraft necessary, as well as rotary wing aircraft for ejected pilot recovery and ASW functions. Drones could be a force multiplier, but they, too would have to be STOL to function with a reduced sized vessel.
Could this package be stuffed into/onto a 400 ft. hull or a little larger?
That's one for the Naval architects, but smaller, yet still highly capable carriers/air wings might be key to bringing elements of a dispersed force into contact with larger enemy forces, yet being more difficult to attack by virtue of their dispersal without the enemy tipping their hand as to their presence and location.