Quote - if PMD files could be read for figures that don't have empty delta files it would be a great solution instead of -inj poses...
Or at least an alternative?

They already work like that.

Quote - Maybee if there where some add ons to take advantage of it and also the option if a figure uses PMD or not... (if I understand correct if you turn it on everytime you save a figure a PMD file is saved also?)

However I have heard so many times that they make poser act strange that I have deactivated them from the start...

The "Use external binary morph targets" option only controls whether PMD files are created when something is saved, it has no bearing on them being read when referenced by a file, i.e. PMD files are always read, but you have a choice as to whether they're created.