I looked at the chassis of the R260 which shares the same chassis as the R380 very closely and from what I saw, I suspect one does not really have to get a waste tank as the pad is exposed from the top once you move the printhead carriage aside. As long as you use dye ink, I would think that you could flush the pads by injecting water into it and vacuuming the water with a high vacuum and a 18 gauge needle to rinse it out. If you look the hose will be visible leading from the rear to the front to the side of the printhead parking station.
Haven't done it yet though.
The key thing is to find the reset software for the R380.
I've done a little exploring. It turns out to be a easy fix. On the back right corner there is a single screw. Remove it. On the side above the screw is a slot. Insert a flat blade screwdriver pushing back to disengage the clip. It took a little force. The back corner panel will move a little. I then used a butter knife in the front gap and worked it around to get the panel off. There are tabs all around this panel that need to come lose. Holding that first clip lose with the screwdriver is all important. Inside you'll see the hose. Detach it from the front connect. Gauge where to drill a hole and run the hose through the side panel. I spent 45 cents at my local pet shop for about 2 feet of aquarium hose and a hose connector. Now reassemble.and run the hose to your collection bottle. Good to go.
I have a RX530 and will do the mod. I am worried when I get the waste tank warning as it is not supported on the ssc forum yet. I do not want to have to pay to get a bit of felt replaced or cleaned.
Is there a key press combination on these printers that will work. I have the refill thing down pat with a resetter and the Epson monitor reports as usual. I refill at 30 % to be on the coservative side. Just for info I seal the fill position with hot melt and wrap the spare filled carts in tissue therefore showing if I have a leak.