Hi Pincho Paxton,
for
OTS (One Touch Settings) you can set the "OTS Link Timing" either to "Real Time" or to "Next Bar" (in the Style Setting display). But for Registrations this is NOT possible. Registrations are always executed directly when you press the button.
P.S.
If you are concerned with occasional, unsightly sound artifacts when switching keyboard voices through Registrations: These are usually caused by the DSP (Effect block) switching. In most cases, however, you can avoid them by cleverly programming the Registrations (e.g. manual assignment of certain Effect blocks and / or assignment of Voices to other Right Parts). Or (the easiest way) you simply take your hands off the keys when switching Registrations / Voices.
Best regards,
Chris