If I update my module to use the DNN Manifest format, will it still install on DNN 3.x and DNN 4.x instances?

Right now my module has a 3.x format manifest file, and installs fine on 3.x, 4.x, and 5.x versions.

I just found that out from a little experimenting myself.

I created a 5.x manifest, installed the module in a 05.00.00 instance with no problems.  However, I get an error on a 04.07.00 instance.

This seems to be a bit of a downside, since it means that if you wish to take advantage of the new features for 5.x you have to now package the modules seperately.

It seems like that -- since the file schema is quite different -- that the DNN 5.x version should have used a different extension for it's manifest files.  During install on 5.x portals, it would look for the new extension file, if none found it would use the .dnn file.  During an install on 3.x and 4.x portals the new extension file would be ignored.  That way developers of modules that work across versions could just put two manifest files in to have the module work for both.