You're probably right, I was not aware of the small number of units.
I also thought custom ringtones was a common thing.
Thx for your help
I believe we may be adding this to the Poly D230 as a feature via EN-167650 so I suggest you work with a Poly reseller or sales engineer if you are after this feature.
The VVX D60 is end of sale to my own personal knowledge.