Display Control with custom HTML?

We want to use multiple observation controls on dashboard but for few (depending on concepts) we want to have a different look and feel (ie HTML).

When looked at the observation control the HTML file name has been hard coded here

Instead can we pass it externally say through config file so that every observation control can display the required HTML.

We know that there is always an option to build custom display control but that means writing our own SQL query which is not necessary as everything (the data) is getting fetched properly in observation control. It’s only matter of disassociating the specific HTML with custom HTML.