Here is a node for a Lemniscate curve.

Also, after puzzling over how to use an arithmetic progression to duplicate the "t" parameter for parametric equations, as is often done in scripts,
incorporated in the Lemniscate node is a nodeeditor Macro, to make fractional "t" values, from 0 to 2PI.
First tried with sinewave node.

From the loaded Lemniscate node in the nodeeditor canvas,
the Macro can be right clicked, and Exported to the Appdate>nodeeditor>macros directory, for future use.

Thought I'd apply an "amplitude" Blend to the center line of the "infinity" symbol (FatLines) Lemniscate.

- Brian

I may try to modify (Max's?) FatLines script, with a separate line for the slider.