@paulrob Thanks for your response! I think I'm bound to V3.2 because of the EAP's being V1. When I got it, it had version 5.something and it wouldn't find my ap's. The only solution I could find at the time was to flash V3.2 onto the OC200, which did solve the problem. But if I could somehow get the EAP's to work with a more current version of the controller, that'd be amazing. I'm a bit concerned I'd have to replace them though...

So it looks like this switch would currently not be adoptable by my OC200. On the other hand, I don't actually need any advanced networking features at this moment, so as long as it has a few PoE ports, it's good enough. I'm sure at some point I'll upgrade the EAP's (it's just that they work quite well and I have no hardware that supports wifi 6 or up) and with that the controller version. Thanks again for the info!

  @paulrob alas, it is as I feared. I hope it's not as much of an issue with newer devices. Considering the network is simple (the controller only controls the access points) I'll ignore the fact that a new SG2218 doesn't work with the current controller for now, and at some point in the near future I'll update the access points, upgrade to controller version 5 and adopt the switch then. Thanks again for your help!