Support "IN" in API Calls

I'd like to be able to make a call for projects that are in either planning or current status- the OR functionality supported in the API fails when there are more complex criteria included with the call, so I'd like to be able to search for project that meet my criteria while leveraging the "IN" modifier. For example:

https://[DOMIAN].my.workfront.com/attask/api/v10.0/PROJ/search?status=PLN,CUR&status_Mod=in

I find it odd that "in" isn't already supported, as "notin" is.