Any supplier over 50,000 customers is now obliged to take on 2 MPAN restricted meters although they will only offer the single rate. I have also a note from Ofgem to confirm they should only charge 1 standing charge for these 2 MPANs. As well as SSE, another example of this is Scottish Power Comfort Plus White meter but like most of these tariffs, it is very expensive. Many will be better off using a single rate for a very cheap supplier as their rate may be only a little more than the 3 rate supplier’s night rate.
As an aside, the radioteleswitch signal switch off has been delayed but will happen eventually. As I understand it, the meters will continue to switch at the arranged times but they will no longer have the flexible off-peak timings which the teleswitch enabled (extra heating in colder weather for example).