A31 Firmware Embedded AP Update(s)

I am a quite happy owner of (2) A31 Dome Lite 2 cameras. I have a question regarding discrepancies between the Firmware and Embedded Ap between the 2 cameras.

Here's the specifics:

Unit #1

Model A31_SS_IPC
Firmware 22.0208
Embedded ap 2.3.38.12167

Unit #2

Model A31_SS_IPC_1
Firmware 23.0526.*.* 
Embedded ap 2.3.38.12247

Obviously Unit #2 contains revisions to the code installed in Unit #1.

I am curious what issues these revisions addressed. Is there a plan to push an upgrade to Unit #1?

Thanks