If an enterprise won't want to pay for the product, what makes you think they're more likely pay for support?
If you're implying they'll only pay when they've seen the value of the product, then the non-pro part of the framework is incredibly feature-rich and can easily do that.
Yeah support model for a lit of projects like this doesn't work. Even companies like the one behind NATS struggle. It's almost contingent on you building a bad product that needs support.