It takes approximately 20 seconds to memorize a table of both the old and new designations and the frequencies they represent. Just learn them and move on.
Easy for you to say. I've been in AMSAT and worked lots of the birds for 40 years and still would have to look up any of them to be sure. I know A is 29 MHz down, but what uplink? I know mode J is 435 down and 2m up. And I think mode B is the opposite. But even those I have to look up TO MAKE SURE. Then there is K, KN, KS, X, C, Ka, Ku, L, S (which S?)
Why should I have to look anything up, if we would just ID the frequency band in the first place.
A few letters to represent frequencies isn't a big deal.
Depends on how old you are and how stubborn. Im' at the end of the scale on both.
Bob, WB4APR