Been writing them for months now. However, let them try and enforce a UBC because it will never work. The only way they can enforce it is by keeping a registration log. There would be no way to prove if a firearm was sold without a BGC unless there is a registration database.
I disagree, if a BOS is required by law to go along with the BGC. If you don't have a BOS then it could be assumed that you sold without a BGC. Your point may be why Congress is discussing how the forms will be kept though. They may say that you have to turn in your BOS to a gun store for them to keep with their 4473s.
Besides, there are tons of people that require a BOS and there is no law that requires it. Once it's actually law, almost everyone will require a BOS. It doesn't matter how or if it's enforced at all.
Will it work well? Absolutely not! That's the next step in their evil plan. They'll get most people used to the universal BGC. Give it a year or two. Then, they can come back and say that people just aren't doing a good job at keeping those records, the system isn't working as well as it could... let's just use a database, it'll make it so much easier for everyone.
bam, real registration.