Sorry, I know I sound flippant.
The SDK kinda installs itself where it installs itself, with all its scripts dependant upon that install folder. It wants you to create a special user, just for it to install into it's user's home. I would have to change it's install script, which while doable, would break the current work instructions (for subsequent programmers at my position) to grab the originals from the repository and run them. It's not that that's impossible, or even all that hard, except for the paperwork.
The amount of work to create an extension would be much less than to create a system that did what I want. I recognise this. It would however add the feature that different areas were updated automatically and independantly, reducing wear and tear on flash devices.
I'll look into how to do this myself (perhaps some shutdown script that autogenerates extensions), and report any positive findings.
I have another project involving getting CUDA development to work repeatedly in TCL, which has gone frustratingly. I got it to work once, but I lost it on a reboot, and haven't managed to regain it yet... It also has an install script (actually one huge file, half script, half encoded binary), that again, pretty much does whatever it wants. There's three flavors, SUSE, Ubuntu, and RedHat. I would have prefered Slackware or Debian, but you gets what you gets. Ubuntu's has installed with various fiddling and modification to half baked instructions for various forum posts, though not permanently.