They do…it’s called the H9000!!😉
Seriously (sort of) what you’re asking would completely change the whole point of the H9. The added complexity would undermine much of the simplicity that makes it popular. I’m not saying that Eventide wouldn’t possibly make a more powerful stomp unit, but it seems they decided to go down a different avenue with the dot9 pedals. I play a Fractal FM3. Fractal has 3 levels of processors that all use the same software and similar DSP’s, but are different in terms of power and size. People are always missing the point on the Fractal forum wanting the lesser (FM3) to do more, but love the size and others wishing the powerhouse was smaller. Companies have to pick a form that meets the most needs at certain price points. It’s not easy with all the competitors and now with chip shortages and supply chain problems.
What many did was buy another H9 core and then have two Max’s and get a lot of effects for the money.