In Ardour 2.X, there was an option to phase invert a track or bus hidden in the context menu for the track/bus name button at the top of a mixer strip.
In Ardour3, there is one phase invert button per channel visible in the mixer strip:
Would it be possible to make this a compile option?
My screen reel-estate is quite precious to me, cause sometimes I’m using lots of plugins on a channel.
Have you already tried Ardour 3 ? The pre and post plugin area is now combined so provides more space anyway, so the addition of the phase reverse buttons may not be that much of an issue.