This describes a lot and actually sounds pretty similar to the idea behind my setup. I have one nurtured and condensed view on the important parts of my system but with more details in the background. One example is the speedtest integration I presented a few months ago. As you can see, there is a nested menu for it but only one summarized line on the main sitemap.
Besides providing a nice sitemap, which I still find pretty important, my home automation is also aimed at “automation”, without the need of user interaction.
Instead of additional sitemaps, I have this one last line in my one sitemap:
sitemap ... {
....
....
Group item=Whg label="Alle Elemente" icon="house"
}
With “Whg” being my all containing group 