It is planned to implement this functionality eventually. With the current database structure it is easy to find all cards with SRSLevel 0 OR 1,2,3 etc… But to get 0 AND any other SRSLevel cards at the same time requires me to look through all that users cards and then lookup all the progress documents related to those cards and then returning it… This is very slow and has a large impact on the server. But has to be done that way due to potential sorting (actually it’s the reason I havent been able to implement other kind of sorting options either…)
So unless I find a solution to this problem, I wont be able to implement it except as a OR situation…
Hopefully I’ll find a proper solution sometime soon but I’m afraid it’s either going to be very slow or require a complete rewrite…