So essentially you pay your engineers to maintain a fork, so you can use the software for "free." Then the question of "build vs buy" eventually arises, because

So essentially you pay your engineers to maintain a fork, so you can use the software for "free." Then the question of "build vs buy" eventually arises, because maintaining a fork is a costly maintenance burden, and is essentially the "build" side of that question. Seems like the license would be working as intended then. ;) Besides, this assumes you're creating a competing work. Most use cases of FSL can self-host the latest code. That's the whole point.