Hi Mak,
Not sure if you were IFR or not but the low level corridor is there specifically to reduce transits through Liverpool and Manchester zones.
I know the low level like the back of my hand but I suppose it can be daunting for people who do not use it regularly.
Manchester do sometimes afford routing directly over the airport, which is nice, but this is at their discretion and tends to be done during quiet periods and I suspect (although could be wrong) is done more for aircraft they are familiar with working - i.e. out of Barton and Blackpool. It is reasonably common for Manchester to allow Barton based aircraft in particular to route direct during quiet periods.
Bodie