Pinned straw:
Just partially answering my own question.
Duratec has guided for FY23 revenue of $465-495m and an EBITDA of $36-39m. Based on their previous EBITDA to NPAT conversion this would be a FY23 NPAT of about $23-25m which equates to a net margin of about 5% (23/465).
So yeah net margins should double in FY23 according to calculations.