[04/30/2020] I have completed assembly of this on my bear frame. As a result I've made a few modifications to the files to allow for better wire feeds and easier access to one of the screws. Installation is still not trivial and I found my power cables to be a little shorter than desired. They were cables I had previously replaced when I switched to my meanwell power supply so I can't comment on the stock cables. My first test heat cycle used a meanwell 12v 320W power supply and got the bed with a Thekkiinngg textured sheet to 100deg in 6 minutes. I didn't capture the before speed.

++++++++++++++++++
I've created a new module for JuanPuchol's Universal Einsy Box (https://www.thingiverse.com/thing:4231370). This module will house a BIQU Power Expansion Board (Mosfet) for the heatbed. I still have an MK2.5 with 12V heater, so this should be useful to me since I previously fried one of the mini-rambo connectors. It will also hold Chris Warkocki's NeoPixel board on the top. I don't have one of these, so I can't confirm there is no interference with an einsy or skr or other board.

Print instructions

I printed in PETG @0.2mm layer height. I had a little issue with warping, but might just be my printer setup. The print in the picture is a previous rev of the model. I made a few adjustments but have not yet reprinted it.

Here is the Bill of Materials:

For the mosfet:
1x Heatbed mosfet: https://www.amazon.com/BIQU-Heat-Power-Module-Expansion/dp/B083Z79TN5
2x Wago Connectors - p/n 222-413 (https://www.amazon.com/222-413-LEVER-NUTS-Conductor-Compact-Connectors/dp/B07JJ6JGTV/ref=sr_1_2?dchild=1&keywords=wago+222-413&qid=1587917305&s=electronics&sr=1-2)
4x m3 hex nuts
4x m3x0.5x8mm cap screws
12 or 14 gauge wire. The mosfet likes stranded wire and the wagos seem to do better with solid core. I'm using the stranded wire that comes with the mosfet.

For the neopixel board:
4x m2.5 hex nuts
4x m2.5x0.45x8mm cap screws

For the cover:
2x m3 Square Nuts (DIN 562) Same as ship with Prusa Printers
2x m3x0.5x8mm cap screws
Note that I largely copied the geometry of the Pi 4 UEB case which might have been setup for a 3d printed pin to snap in?