Alu panels being powder coated.

Dropped off the aluminium panels to a powder coating company in Cardiff. I will hopefully have them done by Wednesday at the latest. The only worries I have with this process are: if I flex one of the panels too much the coating will crack. The company told me that there was a bit of play with it. The other problem is that the coating adds thickness and the holes for the 3mm screws will get smaller. I have allowed 1mm for this by using a 4mm drill bit on all the holes but if the coating ends up quite thick then I will have to file them down for the screws to fit.