I've put together a vector editing tool to help people making games in pico8 use 2d vector animations. It's a web based app and you are free to use it to make any vector shapes you want.
It supports animations, layers, snazzy retro alternating colours and a demo cart to paste your creations into and see them running.
The way the demo cart displays vectors is similar to how pico8's displays sprites, with an x, y, scale and your choice of animation frame.
Try it here: