Preventative Maintenance tasks - assign to non SDAdmin roles

With our installation of SDP, I have about 20sites, and 20 technician with some technicians associated to multiple sites. I have 3 SDAdmin roles, and all other Technicians are SDSiteAdmin's. I need the Technicians to be able to fully manage their sites, but I don't want to give everyone SDAdmin role

My problem is that I can't seem to find a way to add additional functions to the SDSiteAdmins role such as "preventative Maintenance".

The Create new Role isn't very helpful either, as the maximum that gives me is SDSiteAdmin, which severely limits what could be a useful function

How do I do I solve this problem with SDP? If there isn't a solution can it fixed ASAP please?

Thanks

Alan