I can’t see that open-back headphones appeal to me. I am about 20’ away from my rig and although I would consider a cable, what’s the consensus on BT headphones or a combo BT / cabled?
If you can’t have any sound leaking out of the headphones and want a more closed-in and intimate soundstage then closed-back headphones can be fine, but if you prefer a more expansive soundstage and a more “out of the head” imaging/soundstage experience then open-back is the way to go. I’ll also add that most of the best headphones extant are open backed. Also, if you at all care about sound quality ditch the Bluetooth and spring for a cable. End of story. While I almost always recommend a headphone amp with any decent headphones, I’ve read McIntosh may design their headphone section differently and may be perfectly fine, especially just to get started. I’d check with Mac to see how your pre’s headphone section is configured, but eventually a $500+ headphone amp will likely provide meaningful improvements.
All that said, if I’m recommending headphones in the $500 range it’s the Hifiman Ananda with their newer Stealth magnets that’s being offered at a substantial discount right now — $599 down from $999. They’re also relatively easy to drive so your Mac shouldn’t have too hard a time with them, at least to get started. I own their $1600 Arya Stealths that are stellar and I’m gonna have to spend almost double to get a meaningful upgrade, and these Anandas incorporate much of the Arya’s technology. I can also help with a headphone cable if you decide to go this route. Anyway, that’d be my recommendation FWIW, and welcome to the wonderful world of headphones. Hope this helps, and best of luck.