www.makemkv.com

From what I can see, all the documentation for makemkv seems to imply that special characters are replaced with underscores in the filename. However, recently I've been ripping files which have colons (:) in their name - and these are replaced with hyphens, not underscores. Is this something that can be changed? I couldn't see an option for it anywhere - and this behaviour is still in the current version I have installed (v1.18.2, running on macOS on a m-series processor - if that makes a difference). Thanks

As you can see, there are no options in the MakeMKV options or settings accessible via Expert Mode to change the default character substitution rules. If you want to, the only solution to apply your desired naming convention is to use a post-rip automation script that is executed after MakeMKV is finished.