There’s a lot the game could do with the freight on the mainline, with various depots scattered across the line that could be used for more interesting scenarios. We could have more cement tasks where you would have to fill and transport the aggregate to other yards. Also they could have other locomotives like the class 07/08 move MK3 carriages around old oak common for HST services. I feel dovetail is neglecting the mainline slightly but could improve it with this DLC.
The freight runs on that route are rather repetitive and lacking in interest. Unfortunately, it's set in 2015 and by then trip workings such as you describe would probably be carried out by road vehicles. I live near a famous loco depot and everything is delivered by road, fuel oil, wheelsets, spare engines . Have you tried the Tees Valley route? Much more interesting freight activity, but even there, there are sidings which we never get to use.
