If you save V4 as a scene file, with the morphs injected but zeroed, then you can apply a pose preset saved from your character and only the morphs you need are loaded into memory. As yet there isn't a way of making an inj pose that will load the needed morph automatically, though there's meant to be an update to Injection Pose Builder at some stage (once that's out you could use the Poser format exporter to save a PZ2 with your morph settings and process that through IPB to make an Inj/Rem set).