Tye
I have a 76 and and simply search the first letter or two, and it is right there. In the menue/keyboard control/Utility/p3 or 4, there is a choice of numeric or Alphabetical. You can switch back and forth at will.

Since the registrations are self numbering/lettering, I haven't organized anything, although I may in "Blocks" if they behave.

As far as your SD1 method, I have no knowledge. I am new to Ketron.
Bernie