Maybe you should ask HP for a feature request. They haven't been afraid to change the software over the past few years. It's too bad they couldn't be clearer in showing the end users their aspirations.
8 tiles wide limitation theory - will have to test this when I get time.
Where do you think the best place to make feature requests are? I'm not sure if HP is going to add any new features for the Z3100, but maybe the Z3200 or future models should have better nesting features. Well, better documentation would be a start.
I'm pretty certain the nesting maximum is 8 across, since my 2 minute delay setting after each upload doesn't show up after the 8th image is processed. ie. the printer no longer pauses for 2 minutes and it starts the entire nested job immediately upon receiving the 8th image. It could be based on file size(s) or resolution, etc, but I haven't tried smaller jobs than the 4"x6" ones. Controlling rotation would be nice since the printer decided to nest them as 8 across of 4" = 32" on a 42" sheet. The nesting seems pretty simplistic since it could have saved 2 of them (for the next run) and went for 6 x 6" across, but I don't know what the minimum vertical height is, perhaps it doesn't like a 4" long print versus the 6" long it chose.
I'm not certain if it only does 1 horizontal nest across or if it will do a grid of sheets. From my suspicions it looks like it is a very simple nesting function which will not grid the nest.
As well, it defaults to putting the minimum (5mm) border around the full nest. There doesn't seem to be a way to print entirely border free, but at least my nested images were fully butted up against one another like I specified. I guess I can try turning off the cutter to see if it will save 5mm of space between one nest run and the one following.
It sure is a lot less featured than something like imagenest, but I'm cheap to shell out the $599 for the extra nesting functions at the moment since I'm not printing that much volume from my Z.