In some interesting news, Scott from Your Experience Guide was told on a lift hill climb that Colossus is getting a technical upgrade for 2024 that will result in restraints being able to be released individually. This will mean that when a rider doesn't fit or needs their restraint adjusting, their restraint can be released on its own as opposed to the current situation where every restraint on the train needs releasing and rechecking.
This should really help to improve throughputs on Colossus, as by my observation, the constant need to release and recheck all restraints due to guests not fitting or restraints needing to be adjusted is one of the biggest bottlenecks that's hamstringing the ride's throughput at present.
Source:
(Go to 2:55 if the timestamp doesn't work)