I am not sure, but you may be able to get smooth transitions from a Yamaha if you change sounds WITHIN a Performance. Doubtless you already get them by switching between UPR1/2/3 while you hold them.

And, pretty much ANY keyboard short of the new Kronos (and even that has limits) will get a hiccup in the sound (if not a total cutout) when you go from one Performance to another with different MFX insert type effects, as the effect algorithm changes. Even Roland's do that.