Thanks for your remarks, that explains things!

Although, my issue is not about building it, but hovering over an existing signal to see where to build the next one.

As I see it, the current behaviour (apparently intended) actively discourages building signals on curved rail.

So, yeah, I would ...

Yup, that's it. When I rotate (with r) the signal until it agrees with the signal already on the map, it works, otherwise not. Feels like a bug to me.

Another addendum, it depends on where I pick the signal from - if I use the pipette tool and pick the signal on the top, I no visualisation. IF I pick the right one, I get one.

It might depend on the rotation of the signal or something like that?

I've attached a picture, maybe that helps. I am currently holding signals in my hand, and am hovering over the signal on the right hand side.

As you can see, no wagon visualisation. When I hover on the signal at the top, I do get a waggon visualisation.

Likewise, when I right-click to remove the ...

I think the screenshot explains it without much words - the visualisation shows only space for two waggons/locomotives, but trhere is actually space for three.

I think I pretty accurately described my use case - can you ask a more specific question?

The problem is very simple - hovering over a signal while holding a signal in your hand often does not trigger visualisation - removing (right-click) and building the signal will fix this, but when moving ...

In 1.x, I often found myself building signals "backwards", by taking signals in my hand, hovering over an existing signal, then finding the place X wagons back and putting a signal there, rinse, repeat.

This unfortunately has been removed in factorio 2.0, and I can't see a setting to bring it back ...

Great mod, but would it have been to much effort to mention in the ChangeLog that the new version no longer works with the stable factorio version and requires the experimental version?