I have had two screen stone 'star' chips repaired in the past (other than the Aceca non-repair). Both successful repairs were well over 10mm in size, one nearer to 20mm. Both were were successfully repaired (so that you couldn't really see them!) by different repair firms and neither mentioned that there was a 'maximum' size beyond which it rendered a screen non-repairable.
Maybe things have changed, but maybe the small repairers do all they can to save a perfectly good screen that has suffered a stone chip, whereas the bigger companies would rather sell a new screen
?
cynical? - I don't think so.
Glenn Burnage
ACOC member