I spent the last 4 days to come up with a solution for Firefox (keeping 25 cubes below 100 polygons), the idea is to show only 3 faces to each cube, and give 3 more faces to the one(s) that rotate at a given moment.
It's hacky and dirty and adds a ton of code, but it kinda works. :)
(it's a WIP)
That's a really interesting solution and although it does add lots of code, I believe that it will be very useful for many devs who are facing that problem. I'm going to link to your pens from the article if that's alright with you :) Let's leave this issue open, so that the ones seeking for a solution will find it easily.
@crnacura Sure, thanks I think I also found a way to keep all faces and still look less broken on Fx:
You need to add the cubes of each line from left to center, then from right to center (like: 1 2 3 4 7 6 5)
By doing so, you'll force a little the Z-ordering on Fx even if you have more than 100 polygons (like in your demo).