Problem with Mirror Modifier and Multires

  1. I have a base mesh
  2. I have sculpted on a few levels of multres
  3. Now I want a mirror image copy of the object, with base mesh and multires (eg, multires not applied)

When I add the mirror modifier, it looks fine. When I apply it, with the hopes and dreams of later splitting off the separate mesh, I loose the multires. I understand multires does not like mesh topology changes, and I understand why, but I feel like disjoint pieces of the mesh shouldn’t affect each other. Or, alternatively, I feel like the mirror modifier should mirror the appropriate displacements to the new vertices it creates.

Does anyone know a) a more correct way b) a workaround c)if I have stupidly asked a question which has been asked many times before but am incapable of finding on my own and d) would this be considered a ‘bug’ that I should report.

here is a .blend, with my object, and an empty to mirror across.

p.s. this isn’t just one object, this is just an example of 16 or so and I fear I am about to learn a hard lesson in workflow. Should i have mirrored the base mesh, then multiresed, then sculpted with symetry, then split the objects?

just tried that, and it works fine. So, going forward.

Also, just discovered the mirror operator.