Interesting project but we are not a free design or code writing service. We will be happy help out with your design and or code but first you have to make an attempt to design it, write it, post it and explain what is not working properly.
If there is hardware it is always best to post links to technical information as there are many versions of the same or different items. Since we cannot see your project, my eyes are to weak, you need to post using the language of electronics, an annotated schematic (best) or a clear picture of a drawing. Pictures never hurt. Frizzing diagrams are not considered schematics here.
That is not a dance floor. That is a small desktop. 450 @ WS2812 (18x25) in total darkness looks grand, but you can not make any tabletop or dance floor expect total darkness.
The first requirement is to have a tile that is strong enough not only to stand on but also take the extra force you make when you jump on it.
To that extent the second link you posted is not in any way suitable, because it will break.
If the first link is an example of a single tile then how many tiles do you want on your dance floor?
The mechanical construction will be hard and you will probably need access to a laser cutter that can cope with thick perspex (pixel glass)
This project will also be very expensive to make, and it is not suitable as a beginner's project.
I was going instead with a 3D-based construction. a 20x20cm grid. According to my first tests it resists weight and jumping. On the other hand, after that it has the plexiglass part that I didn't look at. the goal would have been to make 4m by 4m by putting these blocks end to end in magnets a bit like on link number 2. I also have the impression that the magnet is a current conductor or that the system of current is hidden elsewhere. Because by connecting several tiles they light up (the first is connected to the power supply)
A couple of years ago I helped design a large system. Basically I designed the electronics. It was a giant 8 by 4 rows of seven (correction 16) segment displays. It was supposed to have a retro look and have a rather grumpy personality because he was so old. He was called "Norman" and appeared at 5 venues thought the North of England. One was outdoors so he had to be waterproof.
This is his first outing at Leeds Railway station.
I designed the system to use DMX to illuminate the segments which consisted of one or two bright clusters lights were these.
It did a lot more, like having a camera and people could send it text messages, and synchronising music and graphics.
Now what has this got to do with your project?
Well it is on a similar scale but people were not jumping up and down on it. And I know how difficult it was to make and store in the Artist's studio, and transport to the site. As well as the problems of powering each individual 7 segment LED square and interconnecting them.
The Arts council funding was £10K and basically in the end all that covered was the parts. So no one was actually payed for working on it. So I know how much your project is probably going to cost.
I think you have underestimated the task you face.
I must be getting old. I see sixteen segments. : ) I like your "larger than practical" project(s). I made an impractical analog clock for a wall. To your point; the hardest parts had nothing to do with the time.
In my very-young years I worked in a club with "disco" floor and bar top. Lumber for the floor was near in size to railroad ties ,and the "plexi" on top was probably near 5cm. It was a long night to replace a broken bulb. We expected dozens to be jumping in rhythm.
I am getting old as you are right and I made most of it.
Yes I can see that would happen.
Here is a link to the website, although the link to me points back to my website that my ISP provided, and then about a year ago pulled the plug on leaving it also unplugged.
