When playing classical pieces, I use more than one finger. The fingering I use is 43214321 or 12121212 when playing notes grouped in 4s. For triplets, I use 432121432121. There are some keyboard players in bands that probably use 2 hands for repeated notes on a lead voicing for doing solos. If I was going to play something like C,C, Octave C,C,C, Octave C, repeatedly very fast, I would use the left hand for the first note of the triplet and the right hand for the other 2 notes. There are other methods that I havent learned yet.