First, apologies for slow responses to blog comments and emails. The MindManager world has been pretty quiet for the past few years and I'm not using it as intensively, so there is a bit of activation energy to catch up on emails and to dive back into Visual Studio to tweak things. Thank you to those who have purchased the add-in.
I don't know to what extent this install is backward compatible with previous versions of Excel. For now it is identical to previous versions in terms of functionality and bug fixes so go ahead and use earlier installs if needed.