Crop & Stabilize Video of a Pipeline

Can someone confirm what the workflow is in the latest (ver 15) Resolve if I have a 4K video and I have a shot that I am filming from left to right a pipe attached to a bridge but the pipe "drifts" (up and down vertically) a little in the shot and I want to crop it to 1080 and remove the "drift" It's been ages since I used the program and can't remember how to do it.

If I recall on the stabilization, you somehow identify what you want to be still in the shot, however maybe this poses a unique challenge in that the pipe is moving through the frame from left to right and I just need to remove the vertical drift.

Well, it looks to me that there's no automated way to do what I want to do because the object I'm tracking is scrolling horizontally through the frame so the tracker window would follow it from left to right when I only want the tracker to track vertically. The object isn't very uniform with staining, moss, etc.

It seems the only way to do this is in the edit screen to use the Inspector Transform tool and just adjust the vertical position of the frame at various points in the clip to compensate for the object drifting up and down. It's not perfect but a marked improvement.

One thing I'm wondering is if the source material is 4K and the project setting is 1080, if I zoom in the transform tool to prevent the black bars, is the final render the same detail as the 4K as long as I don't zoom too much or is the clip downsampled to the project setting resolution BEFORE the transform effects are applied in the final render? In other words should the project settings be 4K instead of 1080 and then just render in 1080 in order to preserve as much detail as possible. Does generating optimized media when the project setting is 1080 degrade the final render or does the final render always use the 4K source files then performs the zooming and other transformations it doesn't matter?