Of course it is. In a paper vote you can mark your vote in a unique, distinguishable style; as long as it clearly shows your intention unambiguously and meets t

Of course it is. In a paper vote you can mark your vote in a unique, distinguishable style; as long as it clearly shows your intention unambiguously and meets the elections constraints it must be counted. So after the vote closes you stay for the count, wait for the ballot with your particularly marked vote to be counted and assert that it gets counted the way you intended it.