Just tell the "Computer" your cruise altitude/flight level is going to be 1000' higher than actual. Just like we F/E's used to do. It will give you a slightly lower differential pressure and a slightly higher cabin altitude.
I'm not so sure about that. These new fangled fully automatic systems are designed not to be fiddled with. I once had a pregnant lady board who was cleared to fly, but had some random pains. It was here flight home a few months before due date. I think this was back in my B757 days, or it could have been an NG. Either way, my fiddling with the control panel settings to try and create a lower cabin altitude achieved the opposite and it was back to fully automatic and she survived. The books don't really give you the insight to fiddle, because they don't want you to. Damn. "that's another fine mess you've got us into, Stanley."