I don't have any problems working with Poser figures in Blender at their default scale - whether to make clothes or face morphs. Set your cursor at 0,0,0 to start. Import, switch to orthographic view and then front view and zoom in.

Blender is great for clothing: Here is a brief outline of how I do a shirt or trousers. 

I start with a cube and build a simple frame with loop cuts and a few extrudes. Instead of subdividing I use loop cuts to get the mesh density to what I want. I have more control that way. I do the initial modelling with a mirror modifier. Apply the mirror modifier before using shrinkwrap (important). For an unscaled Poser figure I use an offset of .005 in the shrinkwrap modifier. Apply the shrinkwrap modifier and then go to sculpt mode to refine the shape and smooth the mesh. Sculpt with symmetry on the x-axis activated. You can switch between sculpt and edit as you need to - that is very convenient. Finally add the details like collars, pockets and buttons if you want to model those.

For a dress, I first make the bodice as above and then add the skirt by extruding downwards from the waist, keeping the mesh density fairly even. Then make the skirt more natural by sculpting it. Shrinkwrap is not good for skirts.

Add the seams and unwrap. Blender's UV-mapping tools are now very good, I see no need to use anything else. I especially like the UV-sculpt feature which enables you to really fine-tune the mapping very easily.

Poser 11 Pro, Windows 10

Auxiliary Apps: Blender 2.79, Vue Complete 2016, Genetica 4 Pro, Gliftex 11 Pro, CorelDraw Suite X6, Comic Life 2, Project Dogwaffle Howler 8, Stitch Witch