Plans on Proberix include features like full-page rendering and change detection alongside HTTP checks.

Full-page rendering, which basically mimics an actual browser to also help test websites that are client-side rendered, is computationally expensive, unlike simple HTTP checks that are good for server-side rendered pages.

The Change Detection feature, which diffs large HTTP responses between two checks, uses a lot of computing power.

I don't want to sound harsh nor demotivate you, but you've picked a very hard market IMO. If you have experience on working on such tool in a different company then leverage that knowledge to build a robust GTM strategy. Innovating technology in this space is hard, I think everything was already invented. The features you mention are already offered by a number of competitors and similar tools, there is no innovation here. Unless you have some very unique value proposition for the users, it will be hard to win a piece of the market.