Why do some pilots feel the need for a Europe wide TA? Surely any transition altitude should form part of your pre departure brief serving to increase awareness of your SSA on departure.
Are you serious? "Keep it simple stupid!". Never flew there, but I couldn't think of anything worse... not only differing TAs but so low. What's the point? Get it up well above where you can at least get the machine cleaned up and comfortable before twiddling BARO settings...