I, too, would really like to see these tiles made legal.
The idea of having a "dead row" sounds good at first, and it might be a good way to go. However, that option presents a dilemma: suppose that both players are using one of Chris' 8x5 tiles, and suppose that both of those tiles can only face one way, and suppose that both players want to be able to 'tuck' their tile under their opponent's tile? Do those players roll dice to see who gets to tuck? Or do we pull out scissors?
Or maybe, continuing the above example, it would just be easier to make a blanket statement that the back row is always required to be the "dead row" (and therefore no tucking questions are necessary). But if we do that, then there could be balancing issues, where a player could potentially make drastic changes to the tactics of his tile for each game (and therefore gain an unfair advantage), simply by changing which way it faces for each game.
In summary, if we go with the "dead row" option, my opinion is that we should designate for each tile which row is the "dead row," and further designate that such a row must always be at the back (and therefore that these tiles can only face 1 way).
...Either that, or allow people to use an 8x5 tile just the same as they would use a 7x5 tile, without any adjustment whatsoever, without removing any rows at all. So the player has 5 additional squares to work with...no big deal!
Regardless, I really hope that the 8x5 tiles can be used in TW play...they're just so cool!