Adding non-standard symbols is likely to break less well tested software. A Ω symbol hosed an early BOM script I was using and adds an unnecessary extra point of failure. Fine to add it to documentation and text but I would steer clear of using it in any file that will need to be parsed by an external program.
EDIT
Here, look what happened in another recent post - and this is in a well tested program & likely at UTF-8 issue. Now, I’m not saying it was related to an Ω or a µ symbol but it increases your chance of problems.