As Wsurfer points out, Autodesk have recent post processors for Speedio models. If properly configured (A tilt, C rotate) they will post code for the M140X1(2). BUT, when you look at the Javascript file of the post, there is no mention of M142 (turning spindle), M303, M304, M305 and other codes characteristic of turning features. Thus, the post will work for 3+2, but won't post for turning (at least I could not find any evidence addressing turning).
From a look at the Autodesk CAM Forum, Post Processor subform, there have been very few comments re: the Brother M140; and no developments regarding the turning functions. Might be worthwhile posting your question there to see if anyone has already edited the post and will share it. Or, if any efforts are being made to develop a post.
Lastly, there are a number of mill/turn posts for Fanuc in the Autodesk post library that might provide clues on how to modify the current Brother post to accommodate the M140.
Fred
PS nickj02, do you have an M140x1?