If I hide rails nearby rails become hidden and as I move new rails become hidden. No rails become visible again, which I assume is the wanted behavior.

However, if I then hit the keybind again to display rails again, only nearby rails are displayed. For those furthest away, I need to go near them for them to be drawed.

You could fix this two different ways:
- hiding hides ALL rails on the map, not only the nearest, and hitting the key again displays ALL rails too
- same behavior as now but when un-hiding, ensure all rails everywhere are displayed again

Also, I noticed you hide the rail shadow too. It would be useful to leave it, since it makes it easy to see where elevated rails are when these are hidden.

Hiding / showing all rails at once can and will cause substantial lag spikes especially on city block style bases. Editing a rail piece causes the whole train network to update, do this for every rail piece around and bam you'll need 2 years to compute all the updates.

That's why I'm only hiding / showing the rails near you.

I did add a special button to hide all rails to solve this issue slightly. You can use that if you want to quickly reset all hidden rails although this can cause lag...

I also did remove the shadow since for me it looked a bit confusing. I may at some point add an option to toggle the shadow.