Can this work without rounding?

[goswinr]

I made an F# port of Clipper2 purely running on float64 without any rounding. I added tolerance parameters instead.
It runs on .NET and JavaScript.
It seems to work well.
I added many tests. All pass.

Now I am curios under which conditions this is not a good idea and might fail?

https://github.com/goswinr/Klip