I'm not sure why, but with the default audio options (and Spotify premium) my recordings only have 160 kb/s, even if I select 320 in the audio quality settings.
Thank you for this workaround! My recordings now have a much higher bitrate now.
In case people are wondering how to configure this:

• Open this file with a text editor: %USERPROFILE%\AppData\Local\Spytify\Spytify.exe_hash\1.X.X\user.config
• Add the following setting in the XML:

<setting name="settings_media_bitrate_quality" serializeAs="String">
    <value>500</value>
</setting>

• The value of the setting is the int value of the LAMEPreset enum, in my case: 500 for the V0 quality (high quality mp3 with variable bit rate)
• Save the config file and restart Spytify
• You should now see the enum name in the settings of Spytify, i.e. Audio Quality: V0
• As a sanity check, you can check the bitrate of new recordings via Windows explorer or ffmpeg: ffmpeg -i "song-name.mp3"