I can confirm it does, indeed, work! IF you are using the same cores in both your emulators.
For example, 
NDS4IOS uses 
DeSmuME, which is the same as the main Nintendo DS core in OpenEMU.
(to check which core(s) are loaded into OpenEMU, just go into the OpenEMU preferences)
So I moved the .dsv file of my game from 
NDS4IOS into the save files folder of the core of OpenEMU.
In the case of DeSmuME, it's in:
	
	
	
		Code:
	
	
		/username/Library/ApplicationSupport/OpenEMU/DeSmuME/Battery Saves
	 
 
Then I just booted the game in OpenEMU and bingo!