Ubuntu 20.04 LTS - Bose QuietComfort 35 ii
Solution 1:
This currently isn't possible; the A2DP profile only allows playing audio, not recording, and the HSP profile that allows for recording has very low playback quality. You can only pick one, which means you have to choose between high-quality playback or low-quality playback & recording.
The good news is that the current release candidate for PulseAudio 15 includes support for higher-quality codecs with the HFP profile, and so you should be able to get high-quality playback and recording at the same time with it. More details are here: https://lists.freedesktop.org/archives/pulseaudio-discuss/2021-May/032082.html
If you're not comfortable building & installing PulseAudio from source, hopefully PA 15 will make its way into Ubuntu by either 21.10 or 22.04.