I run a ton of sports game that go the entire season and what I do is give everybody one BYE week where if they forget and miss, they get the average score of the PPV.
so yeah, its not only a great idea but very fair and practical.
The idea was just to use it for those who joined late.
But we could give everyone "One bye".
Like I said I only question it if someone with a decent lead heading into the last PPV uses it to guarantee victory rather than risking totally bombing....