The E/E lane is something of a leftover from the bad old days, and has no relevance to your zone transit.
Some may remember the days before class A-G airspace, and will recall that Luton's airspace was a combined SRZ/CTR. What this meant was that it was IFR, only if you had an instrument rating.
In order to allow VFR-types in and out of Luton (quite common in those days believe it or not), the E/E lane provided a SVFR routing for use during bad weather. It was never used as a transit route, the two VRPs related to arrivals/departure to/from the North and South.
If you want transit these days, forget about the E/E corridor, simply ask, and it may be granted. North South via the overhead tends to get granted. East-West tends to get in the way
