YES they can. I don't think anyone has clarified this up to this point, so I thot I'd throw in my experience with the T3. It will automatically add SA2 effects on its own. The 2 effects buttons are not absolutely necessary for triggering the SA2 effects - they do, however, allow the player to trigger them when he chooses to do so, rather than letting the kbd software decide.

I've also found that when one has control of the SA2 triggers, they can be over-used or used inappropriately, causing some strange and sloppy non-musical results.

I kinda like to allow the kbd decide where to throw them in. It's cool to hear it do its thing...but to each his own.

All that to say that the S910 without the 2 buttons can still shine on its own with the SA2 voices.

Hope I'm making sense here.
Tim