No replacement as it is not designed to be free-standing. On a windy day, I would not even trust a staff bag to be stood upright in a parking lot. Most cart bag users have them attached to a pull cart or when not on a cart, using a bag stand to ensure they do not fall over. Even my Players 4 stand bags will fall over in the garage if I try to set them upright without using the legs so I lean them in a corner or use a bag stand. Sorry about your frustration with the design, I know its a real thing but just a reality of bags without legs.

A staff bag (or mid-staff) is designed specifically to stand upright in calm, flat conditions. Certainly not in wind or on uneven surfaces. I don't think any cart, stand or carry bag, from any manufacture, is specifically designed to do the same. Even a solidly-built and well-supported staff bag as is typically seen on Tour, is not stood up without the caddie or player tending to it. They are always laid down when left on their own. The last thing you'd want is your bag to fall over in the middle of your, or someone else's, swing or putt.

Yes, a cart bag should be able to stand on its own....in your garage. If you have trouble doing so, it's likely out of balance due to the way the clubs are arranged, or there may be a defective internal support member. This was the case with a new cart bag I once purchased years ago. It was like that when I purchased it, but I did not notice it until all my clubs were put in. I tried organizing my clubs every which way to make it stand straight, to no avail. So I never left it standing unless I was holding it (or it was leaning up against something), knowing the slightest breeze would knock it over. I called Titleist about the issue while it was still under warranty. They replaced it straight away. Turns out it had a bad internal support.

Being a cart bag, I never expected it to stand on it's own other than on a flat surface. I just didn't like the way it leaned when I stepped back to admire my beautiful bag of Titleist clubs! It sort of ruined the image. ;-)