it doesn't work, at least in my experience. Get Mirage Print or some other printing program and power onwards.
Of course it will work. We print all day at my store on Epson printers, using PS and LR with papers sizes up to 64" wide.
From Lightroom the settings are straight forward.
Custom paper size is 44" width, and 36" heigh with all borders to 0". Do not transpose these or base these numbers on the orientation of the image (portrait vs landscape). The width is always the exact width of the paper you are putting in the machine, the height is how long you want it to be cut (or vertical dimension if it is a sheet). If you transpose these, very strange things usually are the result.
In LR, create a cell that is 40" wide, and 30 inches tall. Set all LR borders to 0". Note setting all borders to 0 works because we have no data that is trying to print the restricted border areas.
Note that "portrait" orientation for this paper size is actually a landscape oriented image. So if you have a landscape image, you need to check the portrait orientation checkbox and vice versa if the image is a portrait orientation. I think that sounds a little confusing, but basically "portrait" to the printer means the image does not need to be rotated 90 to fit the paper.
You should get a print that has 2" borders on the side, but probably more like 2.5 inches on top and bottom. This is due to the relationship of the cutter to the print head, and assumes you can trim it.
However, if you want the printer to cut it to final dimensions, you select Roll Feed, Borderless - Retain size. This will then allow you to select the Double Cut option in the Roll Paper dialog. If you do this be aware the print will print a short distance then it will cut the top, then continue to print. Each print ends up with about a 2" strip of paper, so uses maybe an inch more paper than if you trim it yourself.
