Android 5.1 & Group SMS in Messenger defaults to MMS Am I right in thinking that as of Lollipop 5.1 all group messages sent via Messenger are sent via MMS?

In prior versions I had the choice to send them as multiple SMS messages, which is what I want as my contract gives me unlimited SMS messages but charges me per MMS.
I was recommended the Textra app to send group SMS as an actual SMS rather than MMS and I would recommend it to everyone else too. Cost me something like 60p after the trial period ran out, or about the same as 2 MMS messages!