I think a fairly big point is being missed here. If it is VMC you don't need to sit on the ground waiting for an approach to terminate. If it was VMC both the IFR aircraft can cancel IFR and continue their airwork while 30 hundred aircraft depart the aerodrome. It happens on CTAF's in VMC every day between IFR training aircraft. 'Are you happy if we separate visually?' 'Yep'
If you are at Caboolture you're not waiting for anyone, there's no approach there. If there's an IFR doing some sort of let down procedure to LSALT and you had to 'wait' then I'd suggest there's a bigger problem, like, maybe your eyes are painted on? It won't be Class E that forces you to 'wait'
How many days a year at these places are you weathered in, forcing you to wait on the ground until an approach becomes visual? Yet again, it shouldn't be Class E that delays your departure. It will be Class E that stops you welding your aircraft to another.