I think you're referring to the first post I made which was in reference to this thread. The second post was in reference to your plugin.
And just to note, declaring the type shouldn't matter anyway as the default type is a string in the mdo
The type does matter since the plugin needs to know what markup to generate for the ss:Type property of each cell (line 313). Now, I suppose that I could make an educated guess - but since your numeric fields should be typed to ensure correct Store sorting, doing so seemed superfluous.