As I said, with TDR if all you want to do is see open/short and lengths of a few yards, you can get away with murder - as shown in those videos.
But the key features of a TDR are bandwidth (i.e. step risetime and scope input) and good signal integrity. In those respects those two videos show suboptimum results, especially the risetime and signal integrity of the step generator.
With care and a little effort, even a homebrew board and jellybean components can generate a much better step, e.g.
![](https://www.eevblog.com/forum/testgear/show-us-your-square-wave/?action=dlattach;attach=550691;image)
But even then, little beats the pretty and seductive twinkle of an old analogue diode sampler and CRT
![Smiley :)](https://www.eevblog.com/forum/Smileys/default/smiley.gif)
Ought to try to make a video sometime; that ought to be better than a static photo.