However, monthly security patches often require fixes in vendor, boot, or other partitions, which phhusson's ROM won't cover. The AOSP build will only patch vulnerabilities against the Android Framework, but nothing else.
So the question is, what would be the best way to handle monthly security patches? Thinking about it and discussing with phhusson, it seems like it will be a pain in the ass. You would have to download a monthly full OTA, extract all of the non-system partitions, and fastboot flash each of the images. This can probably be automated, but it's not as simple as other ROM updates.