it pretty much sum up with UG wires our POCO do pretty much the same as well here we used 1/0 AL for 400 amp service but go 600 amp they used paralled 1/0's and majorty of them used bundled triplex and they useally dont stock not too many quadplex unless unuseally large service.

Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)