Think about hotel rooms. They so often have a room-width black-out curtain ... and behind it a thin sheer ... and usually some type of non-moveable header (either cloth or wood) ... and they pull open so nicely. While staying in a hotel a year or so ago, I decided that's exactly what I want, so I took a good look at the hardware involved. Hotels have ceiling mounted tracks. Something like this: This ceiling-mounted curtain track can be supported every 2-3 feet, eliminating any possibility of sagging rods as years go by. You can cut them to fit your dimensions, and they're even available in around-the-corner styles. The negatives, of course, are that you'll need floor-to-ceiling curtains, and you'll probably have to do some sewing adjustments to the curtains yourself. Still, I'm going to do this in my bedroom, where I expect to open/close the drapes frequently. I wouldn't do it in, say, the dining room, where I'm going to use plantation shutters and curtains that'll essentially never move.

This is an old thread which I happened to come across in a search to hide vertical blinds in a rental--in my case, over sliding doors. Check with the HOA if you live where there is one because some do not allow the slats to be taken down in order to preserve the symmetry on the outside, especially in "cookie cutter" neighborhoods. Verticals may be dated--but then so are the ideas of many HOA's-- and the fines are very real and can be quite steep. If you rent, you may be charged by the owners for any fees incurred for the violation of some very antiquated and weird rule. And there are some owners who do not want them removed for whatever reason, which can become a hassle when inspection time comes up before rent renewal.

The double rod is not designed to hold grommet curtains. It's designed for panel curtains shirred on the rod, or panel curtains held on with clips or rings. You could add rings that hook to the grommets, but that won't really fix the crowding problem. Try some no-grommet blackout panel curtains instead.

The way my husband did it was to use different EMT parts (connectors, etc.). But if you only want brackets on each end, maybe something like this: https://www.build.com/product/summary/1235285?uid=2956054&jmtest=gg-gbav2_2956054&inv=1&ds_rl=1281078&source=gg-gba-pla_2956054!c1045383044!a55115163721!dc!ng&ds_rl=1281078&gclid=Cj0KCQiA6Or_BRC_ARIsAPzuer8akr68BYUlE-IhCb2A5j-cypiEWOsrkp6earE-f6-kJvLmXPQaQAAaAjEBEALw_wcB&gclsrc=aw.ds or any name brand brackets that will fit your rod size? https://www.thecurtainrodshop.com/ceiling-wall-bracket-for-1-1-2-curtain-rod-each-5425 The brackets will need to correspond to your weight requirements, as will the wall anchors. I assume there would be a header to go into.