[Therion] unexpected warning - cs not supported for surface grid definition

Good evening I've just noticed that a surface definition file that git tells me I have been using unchanged since 2014 is now throwing up a warning in Therion. I made a github issue here https://github.com/therion/therion/issues/681 It affects cs EPSG:2193 #NZ Transverse Mercator 2000 It does not affect cs EPSG:27200 #NZ Map Grid 1949 The warning is triggered with versions of Therion from 6.3.3+ Despite the warning it seems that list, pdf and lox model outputs are produced properly. Bruce