Is the Byondeth curtain rod worth it for heavy curtains?

Here's the bit the listing buries: this isn't a rod, it's nine rods. Each 1 inch diameter section overlaps the next and screws into it, so instead of one thin pole trying to span your whole window, you've got a chain of short, reinforced joints doing the work together. That's the trick. A single long pole flexes under weight because the middle has nowhere to send the load. Overlapping, screwed sections spread that load down the line, which is how a 0.6mm metal rod ends up rated to hold fifty pounds without sagging. It also means the length isn't fixed, you build it out to fit anything from a small nursery window to a wide sliding door, sixteen inches up to a hundred and fifty. And because it mounts to real brackets with drywall anchors rather than wedging itself in place, it works with grommet, back tab, rod pocket or tab top curtains, light cottons or heavy blackout, without caring which one you picked. The trade-off is honest: you're screwing hardware into a wall, not snapping a spring rod into a frame.