These aren't strictly public buoys so I wouldn't. They're used for classes and I doubt the instructors would appreciate the wear and tear, obstacle etc. You'd likely get a talkin' to. They're also a ways from the entry so you'd be swimming them over, not a great plan.
Side-mounting a pair of 80s at the park is sort of impractical IMHO but doable if you're a. pretty big and b. experienced. The burden combined with the hike and the potentially rough entry make it sub-optimal though so you'd have to be pretty determined to dive this way. As you add configurations in your dive career you'll hear the phrase "right tool for the job" and I'd say there are better tools for this entry, like a single tank BC and a pony if you're staying a while.
That being said, I dive a rebi and small bailout and it gives me the opportunity to do some cool dives and stay quite a while with the GSBs. Is it the right tool for the job? Probably not, but I'm determined.