TeddyKGB, like the handle BTW, I do sometimes "intentionally" make the "back end" bet with layoff possibilities in mind. In general, this is stupid - as laying it off, or hedging, gives the book more juice. You are far better off cutting the parlay one play short and betting the last game straight with some portion of the parlay's profit, instead. ( This is true for spread parlays but not totally true for $line parlays where they don't screw you on the juice )
The times it is better to include the last play is if you are doing it to "lock in" the spread/line at the time you make the parlay ( I like to make my plays pretty early to insure against negative line moves ) as you are "taking a lead" that it will move against you in the interum and you don't want that. ( Either the spread will move against you or the $line will before the other plays in your parlay have been decided ). This is what I try, to "lock in" an early line that I like with the possibility of a "layoff middle, or layoff scalp". It doesn't always work, obliviously, but it is far "wiser" to layoff/hedge for a scalp or middle than to do it otherwise where you are giving the out juice for no good reason. I also look for "2nd half" middles on the backend of parlays as those can be a wise hedge that can be very profitable. In general, I advise against hedging, but some pre-thought "could" make it a smart move. Just my 2 cents!