I have 5 AMEX MR cards. While I'd love to be able to carry one and reap the aggregate multipliers on my spend, I highly doubt AMEX will do this. This isn't even offered on the Centurion let along Cent-lite
Maybe Amex will come up with a specialized card that chooses which sub-card should be used for a given kind of expenditure among its portfolio of cards and charges a monthly or annual subscription fee to do that. For someone who is paying $1000+/year in card annual fees, maybe paying Amex $10-$20/month for such a card feature would fly for all interested in customer laziness?