[alecbz]

The whole point of the double-trigger RSU situation is to create a "meaningful risk of forfeiture". It's only that condition that makes the IRS okay with not taxing the RSUs until they're liquid. If employers just top up employees when their old RSUs expire, there really isn't any meaningful risk of forfeiture anymore.

I don't have a full understanding of exactly what language in which laws/documents govern this, but my general understanding is that the IRS would definitely not be happy about that, as it undermines the whole point of the double-trigger RSU.