For sure! Yeah I export the displacement map from the non posed model and then I pose the low the res.
In the A-pose or T-pose mesh I usually make sure to have no tight areas where it would bleed from one part to the other. This projection issue usually happens with a normal map or AO, but I noticed in ZBrush’s displacement baking it does not suffer from it. I am assuming it bakes every quad separately or something like that for the displacement. The way it does it behind the scenes does not cause baking issues in tight areas like on closed lips for example. Only with other ZBrush exported maps does it cross project from one thing to the other causing a bake error. In the case of this project I am not using a normal map to render the body/skin mesh and only used the normal map as a standin detail map in Mari. For the body/skin mesh I will be rendering the displacement map. So I was not worried about the lips for example having baking issues since this does not occur in the displacement map. If I was exporting or baking that normal map for a game I would open the mouth so that the lips dont have a baking issue. Since in that case in games the normal map is my final map.
I did export normal maps for the cloth parts and the sword for the purpose of extracting other maps from those normal maps in Substance Painter. I will also be not using those maps for render as I am going to be using the displacement for any mesh that has a high resolution subdivision in ZBrush. My normal map export served only as a proxy standin for detail within Mari for skin, while the cloth/sword normal maps served as a temporary bake map to extract curvuture/worldspace/AO from in Substance painter for the purpose of texturing, but will not be used in the final render. Those meshes did not have bake issues since they had no intersection.