When I search for something, I can choose between:
I would like to ask adding the Disambiguation note to the list, it would be quite useful. It would enhance the searches like German singer, French band, Italian group, Danish hip-hop, Russian rock etc.
You can already do that by using the search method “Indexed search with advanced query syntax”!
Here’s an example for searching for groups with a disambiguation comment “French band”: type:group AND comment:"French band".
More documentation at https://musicbrainz.org/doc/Indexed_Search_Syntax
In some cases, searching using tags may be a better option. With advanced query syntax try something like tag:Danish AND tag:hip-hop
That’s very true.
But the problem is the Romanian artists are missing a lot of tags 
Searching the Disambiguation note can help one to find some more such artists.
Thanks, those are really useful links
But if you are searching through the disambiguation notes, you can find things “Romanian hip-hop”, “Romanian rock”, “Romanian hip-hop groups”, “Romanian pianist” etc.
General observation: This seems to highlight the need for genres.
Minor concern: I’m in the “disambig everything until disambiguations are no longer useful due to changes in the UX” camp.
But if searches of comment field for country name are producing better results than searches of the country field then we may need to find out why.
Not necessarily.
We already have countries but still it is preferable to write them in disambiguation comment to distinguish same name artists in (inline) searches.