Is there any way to access the pro features of the beta (7.0) with the steam key? I purchased Display Fusion on Steam earlier today especially to re-enable the multi split virtual screens within one monitor and WIndow location saving, but forgot that the feature only supported the odd size splits and location features that I require in 7.0!

I have the Steam version and the beta updates get installed just fine. In your settings check the options page and make sure "check for new beta versions" is checked.