As of MediaMonkey 4.1 the sorting is hardcoded and for music should be on track #. You'll have to make sure though that tags are correct in MediaMonkey (Album, Album Artist, Disc# and Track#).

Custom tag display isn't possible: http://www.ventismedia.com/mantis/view.php?id=8742

Hi!
When I browse "Music" category in my LG Smart TV, I always get wrong track sorting.
It doesn't matter, how they sorted in MM - order in TV always same (maybe by time added or file time stamp).
And I can't do anything, because TV can sort only by alphabet or time.
But when I browse folders in TV (in linked devices), then order is always correct.

Can I set custom track naming for clients?
I want to add track number before track name.
Many other server can do this.
Or there is some setting for sorting?