If you have to keep it straight/even on one limb, you have to- no rules if it sounds and feels good.

I personally prefer pulling a "charlie watts" when I'm widening the pocket and I take the ride pattern out of the equation for the back beat.

When I push a tune I usually just push it- hands together.

Good question.

I'm going thru Fred Dinkin's book "It's about time" (Warner Bros. Publishing) now and there are plenty of examples in the book/CD's on how to do this as well as a discography of different drummers executing the groove behind, straight and pushing the beat.

Awesome book.  Deceptively simple at first glance.

His approach is a "hands together, limbs together one"... endorsed by all the big groove drummers:  Steve Ferrone, Marvin Smitty Smith, Harvey Mason, Ricky Lawson and others.  Having excellent independence in the four limbs, being able to play with a click in the off beats and it dropping out are also emphasized.

Check it out.