As I am providing an additional layer that is completely separate from Leadwerks, there is no reason for Josh to get a cut of the profits. Besides, I have communicated with him in order to make sure there was no licensing problem at all.
Besides, 40MB of .NET will be a necessary update in the next 2 or 3 months. All major developers upgrade to the latest .NET when developing, and since .NET 4 brings significant every day advantages, I can foresee this happening in the near future.
Did you have any problem by saving to the registry? Was there a restriction of any kind, a UAC prompt, a crash, or something? I have tested it in non administrator machines and it works without flaws, although I couldn't do any extensive testing yet. If you had a bug with this, please report it.
Additionally, the registry method was initially adopted for more parameters, but these won't be available in Middlewerks for LE2. A more extensive use of it will be seen in LE3. I personally think it is strange that the engine itself does not record its own installation path to a global access for developers, but that might just be me.