This is not clear if useful, but dumping the idea for tracking purposes.

Some applets could be identified as plugins (needs special permission). In that case, they overwrite the behavior of the API. For example, if some function in the API is broken (either because of the board or because of the scheduler), a plugin may be written that exports a corrected version of that function (possibly importing and using the broken version). When the scheduler must execute this function for an applet (which is not this plugin), it will call into the plugin. Plugins would probably need a special API to modify the memory of other applets, and essentially the same amount of control that the scheduler has.