I can confirm that the dragons don't care about the seat assignment.
Source: I buy the E fare and get in with my Amex Plat. Also, have delta card getting me zone 1.
I do this on every flight. Not for the lounge itself. but rather to pilfer it of a few versions of newspapers or magazines.
Its not that i can't afford more. Its that i like not giving them any more money than is necessary to get from A to B.
If it comes down to it I'm willing to bite the bullet and take their middle seat or check my bag if necessary.