Want to see what is possible with a Dob, have a look here... pages & pages including plenty of deep sky stuff...
https://www.astrobin.com/search/?q=dobsonian&page=1
It's about figuring out the techniques, settings, etc that allow you to achieve beyond the boundaries of what some will tell you is impossible...
Will you be able to take long exposures of deep sky stuff... no, not without an equatorial platform but, can you image deep sky stuff... well, the page I have linked to definitely shows that you can & with some very impressive results....
Have at.. experiment, see what you can achieve....
