In my opinion I think that depending on the base civilization, revolutions should gain a benefit, for example.
Spain should allow its revolutions to build haciendas (especially Mexico)
Italy should allow us to keep the architects and the architects of the revolutions should not cost population. (they could increase the maximum number of architects to 10 only for the revolutions)
Germany should allow us to keep the settler wagon, to be able to create them from the urban centers and that they stop costing us population. (maximum 20 settler wagon)
Obviously I would also add new cards for revolutions, but this is just my opinion. 