Not "20K lux", but I've spent a fair bit of time improving the lighting in my 1970s home. The thinking back then seemed to be "What's the minimum we can get away with", leading to a dark, shadowy mess.
People have been using broken LCD TVs to build "artificial skylights" for years. I came very close to building one, but my wife balked at me spending $50 on a broken 55" TV. :-)
I recommend searching amazon and home improvement websites for "led panel lights", which seem to be a very similar premade light. They come in many sizes and shapes, many of them are meant for 2x2 or 4x2 foot drop ceiling installation, but others are designed for flush surface mount on drywall.
I put, as a test, a 12" round one in our small laundry room, and the light it makes is a great upgrade from the can light that used to be in there.
For my garage, where I didn't want to spend $600 on a bunch of the panels, I got a dozen LED strip lights that look kind of like tube lights, and spread them all over the ceiling. Provides a nice, even, bright light for when I use it as a workshop. However, over the last 18 months I've had pretty much every one of them "burn out" at least once. I'm guessing that it is the 120V power supply built into each unit that is the problem. The vendor has been good about sending me replacements, they have a 3 year warranty, but I think when they fail again (I'm assuming they will) that I will probably look at either just using 24v LED strips directly, and a ceiling mounted Meanwell powersupply, or maybe I'll look at some of these panel lights.
Another thing I want to do for the garage lights is split them into two groups. Right now I have one switch that controls them all, but I have had limited luck getting my kids to regularly turn them off, leaving 300W of lights burning for hours. I'd probably set up maybe 4 of them to go on from the main switch and the other 10 to have another, less convenient, switch for when I'm doing workshop stuff.