I'm Avionic (EIR) and
feel a bit pieved at losing the elec side of my licence(I'll get a B1.1
restricted to Electrical).
If you get a B1.1 you will keep elec but lose avionics. To retain avionics you will need a B2 as well. Although on a B1 you can still do simple avionics tasks, such as replacing LRU's.
When it came to conversions in Europe, it seems the mainland took the pragmatic approach while the UK didn't. But then that debate has been done to death here already.
I converted a ICAO type II licence to a B1/B2 by filling out a one page application form and paying 100 pounds. All ratings was transferred. Which was nice.