Bluetooth protocol. Many Bluetooth headsets switch to a low-bandwidth but full-duplex mode when used as a headset. As a result you can hear and be heard at the same time, but at abysmal quality. Think old phone. You want a headset that supports at least AptX, which supports full-duplex communication at reasonable bandwidth and thus quality.
Spatial audio. Don’t bother! It’s a non-issue that you can replicate in software, with the help of pipewire. I wouldn’t spend money on it.
I’d stay away from proprietary 2.4GHz connectors and stick with plain Bluetooth, as that doesn’t require a specialised driver that possibly requires support from the vendor.