Replace Geometry is broken

[popwfx]

I have a .3b scene with a model loaded for per pixel painting.

it has like 50 layers as you can see from the screen shot and many UV files and surface names. I did a File > Import > Replace Geometry into the .3b to replace the model with a slightly different model - all surface/material names and UV names are identical in both models.

You can see that the Replaced geometry seems to lose the links from the layers to the UV maps for most of the layers (but not all of them which is weird). Also the model comes in with errors (see the yellow errors showing holes in the model or flipped polys - which are NOT in the one used to do the Replacing).

So, if as my previous thread said, that since 3DC does not import models correctly with textures and it takes forever to set up like 50 layers with manually imported color, spec, & depth layers, then that's why I thought I would be able to Replace Geometry would be a good idea to get a slightly different version to use for baking. But Replace Geometry is broken and seems to randomly lose llinks to existing layers despite identical UV maps and names and material names.

This is highly frustrating and needs to be fixed.

In the meantime, is there any way to reconnect existing layers to the mesh? i.e. when you manually import a texture it lets you choose which UV it is assigned to. Is there a properties or whatever that I can access on a per layer basis that lets me reassign the texture on the layer to the model's correct UV?