gloss VS implicit

That Picture type is what does all the heavy lifting. Have you read its Haddocks already? There's an example using play in gloss-examples if it helps you (it just renders the most recent event as text on the screen). When I was new to Haskell and gloss, I found "following the types" helped. There's only a limited amount of things you can do with Picture, and those limitations can help guide you.

Haskell is the purest of the pure, and a fun language. Never done graphics with it but I see Gloss looks decent - https://github.com/benl23x5/gloss.

If you just want to draw stuff on a window, then have a look at gloss (a very simple yet useful interface to OpenGL) and sdl2 (which gives bindings to the SDL library).

This question is in the gloss FAQ:

Ideally, I'd like something like gloss in Haskell.

There's also ImplicitCAD (https://github.com/Haskell-Things/ImplicitCAD) which produces STLs, as it is designed for CAD. It uses implicit functions, which I believe are similar to SDFs (I believe the idea is not to necessarily correspond to the distance function).

ImplicitCAD is essentially OpenSCAD with bevels.

You might take a look at ImplicitCAD. It accepts OpenSCAD code (as well as some other more exotic formats) and can render much much faster depending on resolution. There's an online editor/renderer here that would tell you whether it can handle your existing code unmodified.