SertaMotion Essentials 4 (IV) Replacement Remote Control for Adjustable Beds

can the essentials IV power bed accomodate two remotes for a queen bed?

I want a zero g button, we have the essentials 4 remote though and no 0g button. Can I order a new remote and Synch it to my base?

How to access the batteries to replace old batteried?

Is this compatible with Richmat?