My pennies worth - from experience slow courses are more of a result of the shooters having a good crack between the lanes or between each shooter going to the peg. Would a time limit on the whole session be worth exploring? Clock stops for stoppages, maybe a slightly longer time for 2nd session to accommodate the less mobile? When time is up that's it! Might encourage us to move along a bit faster!
A brace of TX200's
Ex PCP *****!