Many DAZ meshes come in high resolution. Such HD (high definition or high density) meshes can be exported with the Export HD to Blender script, but once in Blender there was not much one could do with them. With the release of Blender 2.90 last week, this has changed. There is a new tool in the Multiresolution modifier that takes a HD mesh and rebuilds the lower subdivisions levels. Following a suggestion by J Cade, the DAZ importer now uses this feature to build multires meshes from HD meshes.
Here is our HD character in DAZ Studio
Export the subdivided mesh using the Export HD To Blender script.
In Blender, two versions of the character are imported, the HD version and the ordinary version at base resolution. They are assigned to two different collections so either of them can be easily excluded from the scene. Both meshes use the same armature, which belongs to both collections.