[css-forms-1] Properties to disallow or force on forms pseudo-elements?

[fantasai]

There's some cases where we will need to limit the styleability of these pseudo-elements. For example, we already resolved on:

::field-text {
  display: flow !important;
}
::field-component, ::field-separator {
  position: static !important;
  /* probably should also add float: none !important; */
}

What other limitations do we need to add?