Getting transferred around shouldn't be a big issue in Kona. There are no boats that wholesale seats on a regular basis like in some areas, pretty mcuh every dive compnany owns thier own boat or boats. If you are moved it's usually because of some type of mechanical breakdown issue and the dive operator is trying to make sure you get a dive in.
Few, if any, dive companies in the Kailua area have a "group ascends when the first runs low policy". I've yet to see it here. Everyone I've worked with or gone out with drops off divers at the boat as they run low and continues on with the divers who have more air. Some companies are more liberal on their bottom time policies than others though, so if you are real good on air you will want to compare operators.
The standard here is for all dives to be guided, so finding a company that sets up buddy pairs to go off on thier own is rare. The few divers I've met who've been hospitalized (twice over the years I've met divers who did their own thing and ended up getting spit out through a skylight onto the rocks with concussions or dislocations) were going out with a company that allowed that several years back. A good DM can lead a group dive, keeping everyone one in sight range and showing them specific critters or structure found at the site without making the dive seem overly controlled.
I'm curious if what you've heard was Kona specific or possibly on another island. I don't think it's common here at least.
aloha,