It's my understanding that Webb used much shorter exposure times than Hubble, correct?

Yes, hours vs days, which makes them a lot more impressive if you know a bit about photography.

I wanna see what this thing is able to do with a 10 days exposure. Let it loose.

>I wanna see what this thing is able to do with a 10 days exposure.

Ever seen a solid white square? =)

As with all things, it totally depends on what's being imaged. Exposing the Orion Nebula for 10 days would result in a totally over exposed image looking like a solid white square.

I trust astronomers to know how to set the exposure.

I want the Webb focusing 10 days on a patch that looks pitch black on Hubble’s 10 days deep field

Exposure time on Webb is complicated. The sensors are different, the sampling techniques are different, and you can get the on board systems to do integration within sets of exposures for you.

https://jwst-docs.stsci.edu/understanding-exposure-times