I get it on the riffs being a lot of standard blues stuff but Liberace does it with such speed and precision. He had a protege "Linda Genteel" who settled near me when I was in Cape May. She had a steady gig in AC and I saw her ther a few times. She could do all the fancy runs and showy stuff like him. Really entertaining.
Not trying to sell you a digital piano but I too am working on some LH riffs ala Jeryy Lee Lewis. I find that changing my FP90 piano sound to a brighter piano makes it so much easier to play those riffs. Jerry Lee never liked grands and use to request an old upright. One, so he could beat it up and I think the second becasue the sound and action allowed him to play faster.
Bill in SC --- Roland BK9 (2) Roland PK5 Pedals, Roland FP90, Roland CM30s, JBL Eon Ones (2) , EV mics, Apple iPad (2) Behringer DJ mixer