I haven't used anything like that, for me the problem isn't tripping over cables but basically the force required to attach the cable in the first place. I guess a magnetic pigtail would reduce the number of times I need to insert the cable but a regular USB-C extension cable would do just as well for that purpose (and that's what I use right now).

That's still not perfect because the 2 cm of plug sticking out of the side of the device is long enough to put substantial leverage on the soldered part inside the device but that seems to be a given. I do try to find the shortest possible plug to minimize that force, but can't find them much shorter than that.