Actually, I forgot to write here my first thought.
The "LOCK = 1" didn't sound right to me. I was expecting more something like "LOCK = ALL SHARED" from the topic of thread.
So every package could be locked to certain build type.
But than again, I don't see how would this work with the inclusion of packages in bigger packages. Should the main package override flag from included packpage? Or follow it strictly (IMHO this one would not work)?
The LOCK = 1 sounds weird to me.. like "you have to do this" without specifying what "this" means.
edit:
Now I see I thought the flag is in .upp, forgot about it being it ".bm".
Still I think even in .bm the DEFAULT = xxx would be helpful.
Well, default settings ARE in .bm and if locked, default is used...