Alt+Click Solo buttons to ‘arm solo’.
Soloing another track will activate solo on ‘solo armed’ tracks.
The same applies for the track record buttons. ‘Record arm’ multiple tracks to record takes from multiple inputs, or record one MIDI performance to multiple tracks (e.g. instant layering of VST synths).
Global Solo/Mute/Record buttons on the track toolbar toggles activation but maintains ‘arm’ state.