First of all thank you for this ROM and all your effort. I really appreciate it.
I have the same issue with deep sleep. I've tried to flash Extra kernel, A1 v1.7.3 and 1.9 the results were the same. Also I tried stock kernel you have provided and still deep sleep was not possible. In GSAM battery stats tablet was always held awake the whole time.
Only thing that worked was to install p7310-Stock-Wifi-xxlpo.zip from A1 thread to get tablet to go to deep sleep.
Any ideas what is the issue ? Something is changed in this release. Previous release had no issues with deep sleep even with A1 kernel.