Why have grade levels at all? Instead, have a directed graph of skills that you need to advance through. Then, in order to advance, you can focus the labor effort toward correcting skill deficits in a dynamic way. This is not possible with how educational institutions are traditionally organized, but it doesn't seem intractable to restructure to support this methodology.
It would remove the stigma of "being held back", as there are no levels in a strict sense, just cumulative progress.
It would remove the stigma of "being held back", as there are no levels in a strict sense, just cumulative progress.