Thanks to all of you who took the time to answer my question and the welcome words to the forum.
Actually, I was reading this forum since the last 6 years probably, but not registered myself until May this year.
Yes, I use one bank of 8 (or less) registrations for each song and many times I am not using OTS but my own selections within each registration. The problem is when RH sounds change within that bank. I guess this has no solution unless by not using sound changes during fills.
Believe me, before I will ever post a question here, I will research everywhere I can to avoid disturbing you with silly questions (and this includes reading the manuals and visit other forums).
My background includes experimentation as one way to achieve our aim, and I use this when facing new challenges on my keyboards as well.
Thanks for the help provided.