Link me to the thread or bump it to the front of the line. I don't see it and would absolutely love to.

It is good to know I am not the only one with that problem. But a delta that big is a worthwhile struggle.

Making progress with Marlin. Very slow progress, but progress. Here are some early screenshots..



If you look closely behind the screen you can see where I mounted the BTT 24v UPS. This guy: BTT UPS 24V V1.0 Resume Printing While Power Off Module – Biqu Equipment
This part is cheap. So much cheaper than an actual uninterruptable power supply/ battery backup. And this method doesn't care how long the power is out. All of my printers have this now..



The only thing about this capacitor bank is that it takes a while for the printer to power down after turned off and then it powers down slowly as the voltage drops and I just really don't like the way it does that. So what I have done is I am using a DPST power switch. 1 circuit is breaking the line in from the wall(black). The other circuit is breaking the power connection to the UPS. This way when I shut off the switch the power supply shuts down and the ups gets disconnected simultaneously and the printer functions as normal with the UPS installed. But if the wall power goes away it is connected and ready to do its job. I feel this way is safer for the mainboard. There is a red led light on the BTT UPS that stays on when it is charged and since the load gets disconnected with the switch after the printer is turned off this light stays on for a good while. I never found good instructions on doing this from BTT or Youtube. But to just leave this connected to the mainboard really makes cycling the power a royal PITA.