Back after another test, where I just tried throwing the entire All Planet Pack + Metal and Stars at this mod all at once.
Firstly, I was honestly expecting at least one of these mods to crash in some way, but it didn't, so that was a nice surprise. Secondly... the organization appears to have been handled gracefully enough (at least as gracefully as it could, between a random collection of planet mod authors that didn't all collaborate towards making all this work)
Between the two images (before and after), and excluding a couple of outliers (like Terra Palus for reasons explained above, and Moshine being too recent to include), the second is definitely preferable to the first.
The only other minor issue is the lower center, to the right of the sun, where most of the new planets appear to be congregating (which makes sense, most of the new planet mods like to fit themselves near the inner solar system: after Nauvis, but before Aquilo in terms of progression). I'm sure that once you get that unbunching algorithm working, the spacing in the lower center part of the image will be improved though.
I'm beginning to turn around on this mod; it doesn't look too bad, once there are plenty of planets on the board. Here's a third, more refined image, with the unnecessary planets (that don't really add any new content) removed.