I bought a portable plastic piano in 2023, and a folding stand to go with it at the time, this KS162 folding X-stand. While I found it be reasonably good, and better than some others, I did have a few problems with it (though the same as many other folding stands), which led to me building my own custom stand for my piano, with this stand being relegated to other duties, or those gigs where I needed something really compact for transport.
It's easy to quickly adjust the height with a sprung handle that clamp and releases a rosette between the pivot point of the folding legs. And it has quite a range of height adjustment, with a good number of steps between them. I ended up putting a few line-up markers on the rosette to quickly set it up to the height of a chair (c), piano bench (b), or a bar stool (s), so I didn't have to play suck-it-and-see every time I set it up.
It has wider feet for the legs and the arms than some other stands, and that should help with stability. But I found the rubber end caps slid off too easily, and could get lost. While supposedly one of them has variable width (as you rotate it) to help balance the stand, I doubt many people make use of that feature. They'll probably just put up with wobbles, or wedge something between. You only have to move a couple of inches across the floor and you get a different wobble, in various venues. I ended up glueing them on. And I did the same on my folding piano bench.
Sitting my keyboard on top of it was not particularly stable. My keyboard doesn't have a flat bottom, and its bottom was narrower than the top struts. And it's not attached, so it's a bit of a chore to move a keyboard around while it's on the stand.
The stand seems quite robust. But because the struts are thin rectangular tubing, it does have some wobble to it. Enough that I found it distracting to play when you can't look at your fingers at the same time. The tubular legs on other stands have more rigidity to them.