Ian, of course you know you could put all 16 voices in a single registration bank, because you have the option of right 1 and right 2, and if I recall, right 3 with the Tyros series, so that would allow 24 custom voices in single bank.
Gary
Of course, you are correct, Gary.
I do have other sounds along with Right 1 for several of the registrations...for instance, I have a Live! Strings patch under the Piano in reg #1 that is set to a slightly lower volume so I can add it as a layer.
Also, my SA Concert Guitar in reg #2 has a Dark Fat Saw synth sound available to layer with it.
I will probably keep adding other sounds to R2 and R3 on the other registrations, and after I've lived with them for awhile, and tried them on tunes, I will store them permanently.
Thanks for the tip AND the reminder.

Ian