Instead of writing an advanced, feature-complete, custom firmware (risky -- a large potential for bricking accidents/more complicated), has anyone considered working on an extremely minimal firmware that simply does the following:
1. Loads another application (this custom application could be the advanced application that attempts to replicate the important functions of current firmware. The functions of this application could probably be limited to things that couldn't brick the PSP, but even so... see 2).
2. Will excute any of the Sony updates from RECOVER folder if found in memory stick root at boot.
I guess my point is that the application defined in 1 would not be allowed to touch any of the firmware region responsible for doing 2. That way any potentially bricking coding mistake during dev. could be recovered simply by updating to a Sony firmware (via what's described in 2), then reinstalling the custom firmware the same way as it was done initially. Both of these ideas may be workable... for the most part I'm wondering if anyone has considered writing extremely minimalistic firmware and replicating any advanced firmware features in a secondary launched app.