So I bought a slider, and was using it on a tripod, but I had horizontal dipping, so without buying anything else, (heaven knows I don't need more stuff) I came up with this solution. It's probably not good on the mechanics of the heads, but it'll work for now.

https://www.pinterest.com/pin/495184921510537172/

Forgive the link post, my uploading ability has always been broken. But feel free to follow me on PInterest.

If you have two light stands you could do the same thing no? I have found a solution using one tripod but utilising magic arms and super clamps coming off the tripod legs and attaching to the ends of the slider using a suitable manfrotto adaptor. All stuff I already had. Works perfectly but is heavy. It does still make it easier to reposition than a stand at either end though. Whatever works though right?

Using 2 tripods?
That is what I always do.
It solid and safe.

I've got 2 the same manfrotto tripods for this purpose with a center column I can raise at least 40 cm. So I can adjust the height easily. I added levelheads to both, so I can make sure both ends are level. Even with the terrain is uneven.

This is my solution.