UV Unwrap modifier (Unwrap model without applying modifiers)

Scenario

• Doing retopo
• Many modifiers stacks (Mirror, Shrinkwrap, Displace, Weighted Normals etc...)
• Wanna UV unwrap the final state of the model.

Issue/problem/Inconvenience

I cannot make a UV map without the mirror parts. I have to apply all the modifiers loosing the ability to tweak the mesh in mirror mode.

Inconvenient workaround

I have to apply all the modifiers and a do the retopo. Later realizing I have to fix something on the mesh that affects both side of the model, then I have to bisect + mirror the object, that fucks up the UV islands. Have to apply again all the modifiers, then do a new Unwrap. Preying that I wont find one more issue with the mesh after I've did the unwrap again.

Expected workflow

Keep the procedural way. Adding a Unwrap modifier that stores a UW map for the full stack. If changes needs to be done, then I fix the mesh, and adjust the UW map on the UV Unwrap modifier if it's needed.

Proposal

A Modifier that stores UV map applied to the final state of the mesh, without applying the modifier stack

Example of modifier lists

• Mirror
• Shrink-wrap
• UV Unwrap (Proposed)
  • This modifier takes the final state of he mesh (based on it's place in the list), and stores an UV map to it. Of curs if u makes changes on the mesh it fucks the islands up a bit, but still easier to do a little adjustment to it than redoing the whole Unwrapping.