Dilemma HO layout plan

[Canadian Atlantic Railway]

That looks very good but I do not fully understand how you will run an operating session.
Where do you start a new operating session with an engine and some cars to be distributed and where ends the session when all car are collected?
The tracks at the top right end would be useful to attach a cassette with a train for that purpose but the mainline is at the very bottom and hardly accessible to add remove cars.

What about running the main closer the the edge of the board along the road, you'd need to rearrange the yard and the cement facility, but it would then allow you to arrange an incoming train close to hand and say the train had just arrived. Return it to the same place on an outgoing train. Maybe you can drop one if the runarounds in that yard giving that area more space. You will still need to be careful with access uncoupling at the industries at the far side of the board.

Just a thought and sorry i haven't the time to draw out what I mean so it either not make sense or make the trackage awkward.

I like the idea of a cassette or I might just stage the train in the yard and runaround. Another option is to drop the rope manufacturer and use that track on the Point Edward side as the "main" and stage over there instead. As for the uncoupling I have long arms and can reach the far side with ease.