@fcwilt Thanks for your input.
A couple of comments on the define in a separate file route. This indeed is a clever workaround to having to duplicate values. At the same time it does strike me as kind of ugly (athough less then what I am doing now 🙂 ). I am not a big fan of spreading around configuration commands in different files though.
You reference mesh.g and after searching the forum I have found a couple of mentions about is, but I have never known this file to exist. It also doesn't not seems to be mentioned in the documentation, nor does it appear among the system files on my printer. What am I missing here? Assuming mesh.g is similar to bed.g, it's existence would be essential to use the above technique. Otherwise I wouldn't be able to introduce my own gcode before and after the G29 command.
The global variable route is an option as well. To me this is less 'dirty' then the separate file. I might look into this while/if my idea get implemented.