you can’t dock it or undock it via staging, but you can definitely use the docking ports as interstages by toggling the docking

(besides using vizzy like what @StarBorn said, which would work much better)

As @YaMomzBox420 stated, looking through the public version of my falcon 9 should help you. If needed, I can send you a POC craft demonstrating it.

you can indeed use docking ports like interstages, that's essentially what they are, except you can also reconnect to them

@YaMomzBox420 helo lol

@YaMomzBox420 Is right. You can use docking ports and use vizzy to deactivate the port during separation rather than using an interstage. You can make a crane and some sorta vehicle to transport the rocket back to the pad.

As a matter of fact, yes you actually can! Granted, it takes a bit of ingenuity and luck, but it's definitely a viable way to make reusable craft. I don't know most of the specifics, but I've seen examples by @Chtite451SR2 and @ChaoticGraviton that use docking ports in this manner. I would check out what they've made for some ideas, especially Chao's "True Reuse Falcon 9" since it was the first proven reuse of a first stage, relying on docking ports for refueling, etc. It also uses a strong back for assembly of the reused booster and new second stage, plus reorientation on the launchpad. Come to think of it, I believe @iSpace made a very similar reuse system (there was an unofficial competition to see who could do it first a few months back and iSpace was barely behind Chaos), but I'm not sure if it was ever uploaded

You can use vizzy