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Thanks for asking.
1) Regarding the Harmony Ultimate:
By default, Logitech does not assign any commands to some of the buttons when creating a PS3 device. Here's an FAQ showing you how Remote Buddy translates commands - and how you can assign the correct commands to the buttons that Logitech leaves unused (click on "Show" next to "Unlocking all buttons of the Smart Control"):
https://www.iospirit.com/support/faqs/remotebuddy/category/23/Hardware-Harmony-Smart-Control/entry/265/-/
2) Regarding the Sony PS3 Multimedia Remote:
The volume and channel buttons on these remotes send IR codes (supposedly to control a TV set connected to the PS3) and AFAIK can't be programmed to send anything over Bluetooth. Since Remote Buddy can't receive any button press information over Bluetooth for these buttons, they can't be used with Remote Buddy at this time.
Cheers,
Felix