Fuel line through firewalls
Vince has got it right. You guys are going to some extra time and trouble to fix something that never breaks. Do any of you honestly know of anyone who had a fuel line chafe through to the point of leakage just because it passed through the firewall?
In my 20 years of flying just about everything except helicopters I have never seen any instance of this happening nor, for that matter, any instance of any significant fuel or oil passing through oversize holes in firewalls.