RT 5.01 says it handles Sigma .X3F files, but not really?

I can’t get it to recognise any of my Quattro .X3F files. Is there a trick to it?

Version RT 5.0-r1-gtk3 for macOS 10.8/9/10/11/12 64-bit - fast

Sigma Quattro files are not supported.

For the moment the only option for processing with RT is to convert them first to DNG with Kalpanika

Thanks.

I suppose I got my hopes up when I saw here (http://rawtherapee.com/blog/rawtherapee-5-released ) the statement, "RawTherapee 5 supports most raw formats, including some unusual ones like those from cameras using Foveon and X-Trans sensors. ".

I thought maybe they had done something new.