Well, i have pictures of 109Es during the BoB of JG53 with MG17 or canons in the wings. Both variants with the earlier canopy and the later one.
Both canopy versions with headarmour and without.
Both canopy versions wih addtional front windscreenarmour and wirhout.
Optical, there was actually no "the 109" during BoB
And yes, because the already confirmed Bf110C-4 is armed with the mineshell firing MG-FF/M it wouldbe easy to make an 109E-4 version...
An E-1would need some 3D overworking.
But hey , the axis will get 5 flyable bombers, two fighterbombers and the mighty G.50

So... I dont think its worth a big whine to have 'only' an E-3
RAF will have only one bomber, not to forgett! So, let them have their multiple versions of Spit&Hurii IMHO