Hello,
this is for sure an old question 
Is there a way to maintain the same UV layout, when I need to remesh?
I have within the last steps of a project issues with a head and need to remesh.
Unfortunately my current textures were for a certain UVlayout.
(I know the reprojecting ability, but this way a would loose for sure sharpness)
Thanks for reply
Not really, no. UVs are dependent on topology. However, you don’t need them when working in Zbrush for the purpose of sculpting, and projection can be used to transfer the detail between meshes that are mostly identical in the worldspace, but have different topology.
There’s no reason you should lose color or sculpting detail if the target mesh has sufficient resolution to hold the incoming detail. You can simply work without UVs while sculpting (and should whenever possible), remesh as desired for the purpose of smooth sculpting, and transfer that detail back to the original mesh with the original UVs, after it has been subdivided sufficiently to hold the detail.
This assumes the meshes are still mostly the same size/shape, with only deviations in fine detail.