When B1 and B2 was invented, LAEs in Scandinavia who had a full ICAO licence were awarded both. They got B1 and B2.
Sorry but this irks me because as a Brit working in Sweden my licence was converted to a B1-1 (and C actually but I never use that).
But when it is time to renew their licence the Swedes have trouble because although they hold B1 and B2 they are mostly split into A and C and Avionics like the rest of us. The A and C guys who try not to touch the electrics are now being asked for worksheets to prove they have used all the special tools they have never seen since they were apprentices, and the avionics specialists must show when they last rigged flying controls and changed an engine.
So depends on your licensing authority, it can be difficult to hold B1 and B2 if you work on heavy jets, and keep up your involvement in all areas.