Are the Lulu Signature Cuffs Restrained Life-Viewer compatible?

Yes, they are, out of the box. Of course, cuffs only implement RLV restrictions that you would expect from cuffs. So you won't find Lulu cuffs preventing you from IM'ing (look to the gags for that), or taking off clothes etc.

These are the default RL Viewer features implemented by the cuffs:

• when locked, can't touch any object more than 1.5m away from your avie. (v1.06.01 and above)

• when locked, you can't detach any cuff or the Command HUD. (v1.045 and above)

• when in a pose that prevents movement, you are not allowed to tp either. Except if the tp is offered by your owner. (v1.045 and above)

Starting from cuffs v2.0.4, the sub's owner can choose to turn any of these options on or off when using the cuffs. Go to the cuff menu (say "/1c" when cuffs are worn, click "other..." and then "RLV Options").

Also, starting from HUD v5, some other RLV functionalities (which are not directly related to LULU toys) are provided, e.g. shared folders and forcesit (forced mounting onto furniture etc.).