GLTF or FBX can be used to store texture animations in a 3d space.
One option I can think of is rendering the particle effects as billboarded textures in GLTF or FBX.
As for handling collisions with objects, Pixel part already has colliders which can handle collisions with objects.
There's already a way to edit the particles in a 3d space within Pixel part right under the "edit" section.
Edit>> 3D Effect
I don't see why not to take advantage of that by rendering the particle effects in a 3d space, exporting to a 3d file format that supports texture animations.