Pappy, in case you tested everything in similar conditions, it is weird that two browsers show different data. Clearing cache may help, or... Ough, just noticed, what do you mean by "custom Mac browser"?
As for your second question, I just posted the following in a parallel branch :
"The evening mode is still a matter to investigate. Try both, AGGN=2, and AGGN=1, and see what do you like more. Some people turn back to Video=1 mode for a night drive, some are able to find acceptable settings. Lets see how the future firmware will improve the night mode."
Thus so far there is not any solution besides playing with all the settings until you reach a picture quality that will satisfy you.