End Point Manager - How can I upgrade some of the phones?

I have Aastra 6739i and can’t program all the buttons from the EPM. You can access the 1st 18 buttons, but no more. I’m looking at the EPM and the $aastra.conf file and I can’t see where I can increase the number of buttons I can assign.

Also I don’t see any support for the 6735i telephone. Any thing I can do to help get this phone added to the supported telephones in EPM?