How to prove or disprove that if a polyomino tiles the plane, it must also be able to perfectly tile some larger polyomino, which also tiles the plane?
A polyomino is finite set of unit squares connected side to side. Allowed to rotate when tiling. Tiles must be disjoint. Perfect tiling=Exact cover.


If I understand you correctly then there are many counter-examples.
A three-tile L tiles the plane, as does a four tile L, but a three tile L cannot tile a four tile L.
Response to Mark Beadles's comment Anisohedral periodic tilings such as your example do tile larger polyominoes. In your example, you could combine four connected octominoes in different orientations to get something like