What would it even mean, though? It would just let them free up other, unencumbered funds, for things that aren't browser related when they would have otherwise

What would it even mean, though? It would just let them free up other, unencumbered funds, for things that aren't browser related when they would have otherwise been spent on the browser. Surely the influence of "wow look at all this money coming in from browser development" is going to influence them to invest it there? If you don't think that then you don't trust them enough to give them money. And that's fine. But this idea that it makes sense to try to put strings on the very small amount of money we're talking about here...seems to imply some naive notion that you one could operate without trusting Mozilla...