Just checked if it possible; and it looks like it is.
the current Mx Search is not much more the adding a xpath constraint to the datasource.
"(contains(Name,'123')) and (contains(FirstName,'x'))"
This could work with this search too, though performance wise it is not optimal, when you like to search a lot columns at once.
The xpath 'contains' functions does not uses index, because it is not case sensitive. Combining it with a lot of OR statements, would make it not as responsive as the demo BootGrid. (Which loads all data in client memory)
I think it will take about 3 to 5 development days. If someone likes to sponsor them; I might be able to schedule this feature soon.
Nice datagrid, the standard would definitely need some improvements. Have a look at the data grid extension on the appstore https://appstore.home.mendix.com/link/app/877/Flock-of-Birds/Data-Grid-Extension-(Flex-Headers)
This will have some similar functions. If you miss any i can have a look if i can implement it for you.