Thanks for making the partitionings clearer to me. I have edited the brainstorm accordingly.

@GeneralAntilles: I understand that the solution isn't very easy, but I have a suggestion (also to be found in the brainstorm itself as solution #1):

Solution #1: Place root in the large flash and link critical files in the fast flash

Posted on 2010-02-09 01:46 UTC by Stefan Möhl.

It seems to me that the current "optification" solution is close to right but the wrong way around. Instead of placing everything in root, and changing big slow stuff to go in /opt, we should do it the other way around. Put the root directory in the bigger flash, and for files that really need speed, link those specifically from the fast small flash. I.e. some sort of "speedification". The reason this is better is that it is more robust. If a package needs to have a file in the fast flash, it can be placed there. But if nothing is done, the package will at least work, just not at optimal performance. In contrast, a package that isn't optified will, if it can be installed at all, have a good chance of making the device unusable by completely filling the root partition.

So, if I understand GeneralAntilles right, the problem is the files used at boot time (and probably a few others). Well, in a nutshell, my suggestion is to "speedify" just those files, instead of (quite literally) optifying everything else in the world.