I am wondering if VL-BB-Ref & VL-BB-Set couldn't effectivly be used in a lisp app in MDI working with a data structure like this...
((<Path&NameDwg1> ((data...)))
(<Path$NameDwg2> ((data...)))
(<Path$NameDwg3> ((data...)))
...
)
Within each drawing, when launched, the lisp app would deal separately with the active drawing's own associated data via lisp code similar to...
(setq DwgSpecificData (Assoc <Path&NameDwg1> (VL-BB-Ref 'appdata)))
... modify and append to DwgSpecificData here.
(VL-BB-Set 'appdata (Subst DwgSpecificData (Assoc <Path&NameDwg1> (VL-BB-Ref 'appdata))))
... your thoughts?