I'm trying to get a pyro simulation to work with objects that are deforming like pumps, but it seems that when my geometry deforms, it passes almost right through the smoke resulting in a visible loss of density. It would be nice if the collision objects actually pushed stuff inward instead of just straight up deleting it, but I'm not sure how to achieve that.

Things I've tried that haven't quite worked:
- Disabling "correct collisions," which definitely helps me to see where all that volume is being lost.
- Using volume velocity instead of point velocity.
- Piping in velocity on the collision object.
- Using the collision object's velocity in a field force. While this helps somewhat, it's a bit odd/unnatural.
- Using the collision object's normals in a field force.
- Using surface collisions.
- Increasing substeps.
- Increasing collision/pyro resolution.

I'm using version 17.0.506. If there's a solution in a newer version, I'd have to look into that.
This uploaded scene is really basic, but gives the gist of my problem.

What you might want to try, is instead of animating the Activation of the SourceVolume node, animate the Source Scale for the Density field only. This will leave the temperature and velocity fields intact throughout the simulation. When you turn them all off using activation, you effectively make the smoke "cold" after the first frame which can cause the visible density to thin out.

Oh, I had no idea that would happen because of that. Is that the only thing you changed? I pasted that code snippet into the source scale and no smoke showed up at all, so I just manually keyframed it, and it still looked like there was loss of density. Yet the GIF you posted I would say looks pretty consistent. Unless you're visualizing it differently somehow. Here's a comparison of the last frame for both ways for me.