Real nice way to balance level of tracks

This is a follow-up to a previous discussion about keeping a reasonable output volume while flipping between different tracks
While the suggestions were good, I still wanted something that would handle for than 1 or 2 or 3 tracks and wouldn’t require too much work (aka ‘thinking’), and came up with an idea with only ‘Mute’ automation for each FX.
Here’s a rough outline:
Each FX is on a dedicated Bus.
Each FX Bus sends its output to a Parent Bus (Parent FX).
The Parent FX sends the output to the Master Bus, and also to the side chain of a compressor that you put on the output bus of your solo instrument.
Here’s an example:
Ardour mixing scheme for any number of Tracks