That is a nice trick!
Another one is to use the monitor-bus (instead of master). That way you can still play the normal mix (and export it) via master, while listening to the reference.
If you use A/PFL, you do not even need a send and insert from the reference track(s). Just disconnect those tracks from master, and then use solo/listen.
I was just thinking a bundle of stock plugins (“official” or “unofficial” / community) on a contemporary basic workflow fashion (just as Reaper, Protools, etc) would be relevant to attract more users from those ecosystems.
I’m not a developer, but perhaps only if there would be some way to stimulate externally development of a certain essential tools following Ardour quality standards whose came to fill the gap around current bundled collection
Maybe offering an agreement to active developers (offering a % of donations, for working or adapting interesting tools for Ardour developers & Community) , open commitment with other ecosystems or call to arms for a summer of code, I dunno… Offering x42 plugins on the bundle would be nice, but I’m still missing: restoration and cleaning tools, a better autotune (Reatune is a good example), filters… (just as Reaper, Protools, etc)
Thanks for your work, is suppose is not that fair asking and not coding or even paying that much. You, guys, rock. Love U 
As a fellow traveler, I am fond of this amorphous “map”. Well done, and looking at Ardour 8 I feel that the guiding principle has brought you all to a reasonably fine place. Complacency can be a foe, since most DAW users are sheep (“what do DAW users want”), in the sense that we are using received systems that have mostly been developed with commercial interests in mind (and so the common good??).
As trailblazers for artists Ardour could do even more, I believe. Most DAW development seems to function from a rut, in 2023; copy-copy-copy… And so the children’s book emperor’s fashionistas seem to agree that A.I. is the new chic (somewhere: a baby booms). Hopefully, all dev’s in the queendoms can resist the urge of ‘refashioning’ the basic wheel for 2020-2030s wind-blowers. With feet grounded…
Out of all the DAWs, color coding in a logical and harmonic fashion is something that Tracktion has attempted thus far (I mean: full scale). The use of visual cues could be developed. I like to joke that a band or orchestra swaying in unison (or not) is a first step in quantization. With the eyes closed, we rely mostly on auditory cues. Thank you 
I really don’t like bundled software. If “stock” plugins become available for Ardour, please make them optional during the install process.
Agree, I’d add as an optional in installation process (or after installation by repo), BUT mostly as a strategic guideline, modelling a proper “experience” for new users can find from the very beginning even before they decide came to Ardour and for the future of the ecosystem (became a true alternative for most users). A sort of leadership for stimulate some community developments that aren’t critical for Ardour itself, but convenient for its growth.
I don’t get it. Does the Insert mute my session when I activate it?
There is an AB plugin from LSP, if you ask nicely (and time allows), they might add reference file playback from HD. Right now you would have to load your file into a track in of your session. Pretty impressive plugin though:
https://lsp-plug.in/?page=manuals§ion=ab_tester_x8_stereo
Edit:
That said, thanks @paul and @x42 for the list. The “things no one has done” point of non 12Tet and eastern scale stuff is a lot on my mind recently. I suppose you could only properly implement it once
Figuring out how/where to include scales/modes within the program
is solved.
Edit2: Also, I finally subscribed 
Ardour8 midi and automation improvements cater to my workflow.
I would add midi 2.0 to the list. A lot of questions will come up of dividing tasks up between the host and the plugins etc.
Thank you, @GenGen, @erojahn and @x42 for your suggestions.
Actually, I use Metric A/B, which is a great plugin for that task.
My suggestion is to just improve Ardour, really. Every DAW should have this feature (and perhaps none do?). Referencing is a significant part of any workflow, which means it makes a lot of sense to have it integrated instead of having to use a separate plugin. Wouldn’t that make Ardour stand out from the rest?
Per Region Plugins!!! God and Robin and me know how much this would change things, only feature I really miss since moving out from Audition indeed. 
I would add backward compatibility somewhere in there. It should always be possible to open sessions from any previous version of Ardour without them being corrupted.
This is already our operational policy and when it fails we consider that a bug to be reported at tracker.ardour.org
This does not and cannot apply across vast distances, however. For example, the cross-fade model of Ardour 2.0 was completely abandonded sometime around Ardour 4 or 5, and we cannot load 2.x sessions “accurately”.
That’s a good operational policy. It might still be worth documenting it.
Getting such bugs fixed before moving on to the version after next would also be good policy.
Not that I’m complaining, you understand, but there it is.