Presumably the restriction is a hangover from UK only using EG** combinations, probably around 600 odd of which might be available after a few unsuitable ones might be deemed not acceptable for release.
The geographical distribution of ICAO allocations by leading letter might appear as the image below (caution, just an image found on the internet, not researched at all...).
It might be reasonable to assume that there are many E*** combinations in northern Europe that will not have been allocated and could be made available in this era of electrons rather than human recognition of the second (or even third?) letter region 'identifiers'.
Example: A quick look comes up with EGA* combinations seemingly allocated in Northern Ireland region only and only 6 of 26 possible identifiers allocated.