I have similar problems with subspecies of LBBG, like Gabor has.
This autumn I have quite good numbers of LBBG here in Austria, ridiculous for those who observe at Atlantic coasts of course

There are up to 14 individuals at the large gull´s roosting at the moment. Most of them are 1 cy, the majority are obviously Baltic gulls.
I will show 5 examples. First is dark mantled 3cy or 4 cy (?), it arrived very late yesterday, so excuse quality of this digiscoping. I have determined it as a Baltic, but is it allowed to have so many new primaries now?
Then 2 pictures of 1cy are following, I have identified them as Baltics too. Confirmation possible?
The next one can be an intermedius type...
And the last one seems to be definetely an intermedius type bird.
No ringed one so far.
I hope for confirmation or otherwise correction!
Wolfgang