As long as you have two or three butts ready for each seat when the ride vehicle is ready, you're as efficient as you can get.
Some of the continuously loading rides are somewhat slower due to frequent stoppages for guests who must transfer from
ECVs or wheelchairs. Anecdotal reports of increasing numbers of ECVs and wheelchairs would lead me to believe these transfer stops are happening more frequently than in the past.
Consider, also, that in a system designed to run continuously from start to finish, like the Omnimover, frequent stops and starts place additional strain on the system components, increasing preventive maintenance requirements, accelerating wear, and causing more frequent breakdowns...