That is a dense 50%
Isn’t that related to the width of your filament (hot-side wise) ? I am not sure of this, I always print in 0.4 mm, but if you ask for 0.2 instead, won’t that lead to a twice denser infill ?
Maybe all of that is related to which slicer you use. I was kinda surprised first time I went from 15% to 25% as it was much denser that I expected.
On a tuned printer, shouldn’t you be able to print at 100%? I’ve used a 100% infill cube (it was stairs, actually) to fine tune extrusion. I haven’t ever printed anything “final” more than 90%, because there are some inevitable artifacts at 100%.
I don’t go much higher than 60%. I think it was either e3d or matter hackers that found anything higher just wastes filament. I have a .4mm nozzle, and slicer knows it’s a .4mm nozzle, so it should be accounting for this. It might just be the infile type. The part came out great though, so that’s really all that matters.