I would call this an experimental technique that may or may not work. It depends on how thick the oil paint is applied. While it is fine to work with encaustic over an ENCAUSTIC monotype (ie, encaustic paint monoprinted onto thin rice papers), it is not the same as building up encaustic layers on top of an oil monoprint unless the oil paint is very thin and very dry. Again, I would consider this an experimental technique!