Adding tmpfs mounts

I’m using oci images and would like to use tmpfs for some filesystem paths for e.g. cache directories or /tmp while also avoiding messing with the source image if I can help it.

Currently I’m solving this with something similar to this local-exec suggestion with:

  provisioner "local-exec" {
    command = "incus exec --project foo myinstance -- mount -t tmpfs -o size=3G cache /cache/"
  }

## TODO: https://github.com/lxc/terraform-provider-incus/issues/86
#   exec {
#     script = "something..."
#   }

I would appreciate instead being able to instruct incus to mount a tmpfs at such a directory, similar to tmpfs mounts | Docker Docs

Is there an easier way to do this in incus? (Other than e.g. creating a tmpfs & the host & pointing at it via a dir storage driver etc. which’ll surely go wrong in a few ways…) I’m thinking of a tmpfs storage driver or similar could be a useful feature?