@Akira Tsukamoto
Thank you again, I think that answered my suspicions. You confirmed part of it I think - I have trimmed the rootfs substantially. I am not using automount (hdmi, keyboard or mouse.. and basically headless).. so this could also be part of the question as to: 'what about that folder'.
I suppose I could setup rules and such.. but I have a custom app that manages the sd mount quiet efficiently, as I prefer it.
I believe, perhaps, I need more information about each of the partitions on emmc to understand this question fully. I have tracked down a few places on the web about p1-p10, and observed the symlinks in /dev/disk/by-label and /dev/disk/by-uuid prior to my post. Although, I haven't had the time to go in depth, yet, as I've been busy with other things.. plus I've lost those links as they didn't make it into bookmarks.
Do you have a documentation link for partitions? This would probably clear it all up for me. I believe I last found something on a blind search within the context of fastboot flash <label>(?) It may have been android documentation even, although I'm really only interested in the linux parts for an embedded application.
From the flashall script in emmc rescue, I can see the labels: rootfs boot hyp modem rpm sbl1 sec tz aboot, and so I aware of the corresponding binaries' existences.. but I really need better documentation to fully utilize their functionality.
Should there be a symlink in by-label as well? In the latest build, I would like to understand the full correlation for the underlying partition's purpose.. 
I've rolled my own kernel and rootfs, haven't gotten to boot, much less secure boot, stuff yet.. but soon enough. I understand some of the limitations that apply there.. and open frameworks available for other hardware.
Back to my original question:
I don't really care about booting from sd, and so perhaps this is less of a concern?
