I’d also consider what would drive agencies and freelancers to do this, and market accordingly. This is one of those where many (i.e. those who’ve never experienced an infringement) would regard as an unnecessary cost.

Set up saved searches on twitter for “my work got ripped off!” type posts and reach out with “that sucks, I’m sorry that happened - I have a product that might help next time”. Optimise SEO for terms like “website was copied” and “how can a freelancer enforce IP right?”. Those who have just been stung will buy this in a heartbeat, and a free tier would capture a large and vocal market. Most B2B purchases come from distress.

Finally, consider reworking your copy. It’s too much steak, not enough sizzle (you talk a lot about features and the tech, but not enough about how much better (trouble free, worry-free, easy, relax, no stress, get paid, boost revenue through easy licensing) it’ll make their lives).

Also,

“In a very bad scenario where our service is slow, the worst thing that happens is a user being able to use the web app for a couple of seconds before it is denied access.”

What? I think I know what you mean, but that reads like “if our servers are down, you will be too”.

Finally finally, consider a positive sell too - “license your work with ease, monitor subscriptions”, rather than the purely negative (protect yourself against infringers!) you have currently.