the ability to sound lock and the addition of the sound pool are the reason i would imagine as that is when the change happened. sounds can now be locked to each step of the sequencer, functioning similar to a sample lock.
func+yes is the command to preview samples off the +drive so the preview commands are now more consistent.
I will say that that is the sole unintuitive element of the machine. If you’re sampling a synth, theres a likelihood that you’re sequencing it/playing it from the DT.