Hi Michael,

re:
>I don't really like how it has ended up with new .3dm file versions not being backwards compatible to be readable by older versions of the library.

Yes, that is problem in mainstream sw in general as well as Rhino.

http://docs.mcneel.com/rhino/5/help/en-us/fileio/rhino_3dm_export_to_earlier_versions.htm

Fortunately it exists certain transfer files.

BTW. I had chance to compare Rhino vs MOI soem days ago, and I have to say the intuitiveness and effectiveness of MOI is very addictive :-). Thanks for such great sw.