Others have suggested greasing the dowel or using bearings, and if the issue was friction, then they’d be right.

If the issue is inertia, then this won’t help. Accelerating a given mass to a given velocity requires a certain amount of energy, no matter what.

What could help is something similar to a Huygen drive, where the filament is looped around a large wheel (large enough that the filament can curve around it without breaking) which is able to move against a spring or counterweight. This would allow the movement of the spool to be “averaged out” rather than accelerating and decelerating sharply on every extrusion and retraction.

Fellow OpenSCAD user here. I’d recommend it to anyone as a thing to try, but not necessarily as a thing to certainly end up using.

I love how much control it gives you over your designs and how you can use that to make intelligently parametric parts. I’m continuously frustrated by how it expects you to make (or find libraries for) everything from scratch. For example, I’ve recently discovered ClosePoints which is (a) brilliant and (b) makes me wonder why the heck this functionality isn’t built-in or at least in a default library. I’ve also found that using it for anything complicated has forced me to learn how to write better-organized code.

You still have to put in work to learn how to use it. It’s just a different kind of work.