I ran into the issue back in version 4.1.5.
It was corrected in version 4.2.
If it is not working in version 17.2, they lost the fix between those versions.
Wish I had better news.
There is a tab named UDP in table dialog at columns page. It works there and it's much easier to set them at column level. At least in DM 18.4
BTW - comments, comments in RDBMS and notes can be edited on Overview tab.