Quite possibly I am missing something but here goes:
I keep a lot of file formats in my database that DTPO does not support natively in an attempt to keep everything together in one place. While I love the portability of my stuff, I am puzzled by the lack of freedom it ensues. As far as I can tell, DTPO decides which programs to offer to open a file with that it does not understand itself. This choice seems to be based on what the system knows about this particular file type but unlike the Finder the DTPO “Open with…” command offers ONLY a selection of those programs, in other words it does not offer “other…”.
Is “locate in Finder”, opening the file there using “Open with” -> “Other” a viable (if unnecessary clunky) alternative or will changes here go unnoticed by DTPO?