I've been working on Bezerio, overcoming

[light kestrel]

Can you place tiles/walls along the bezier curve? That's what I really want to use this for.

[thorny roost]

Yes, but I'm upgrading it to place more different things now, walls are simple

[indigo harbor]

Using this as a rail placement tool would make this a must-have mod for me

[thorny roost]

I've been thinking about this a lot, definitely a good idea, but very challenging to implement, I would essentially have to rewrite rail planner from scratch and also have it approximate a curve.
I have some ideas, and it might actually also be a way to solve some of my other problems, but I'm planning to first make it work on walls, tiles, power poles and some turrets first, as I initially envisioned it for defense building.