I should say the triples would be great with the copper shell, I just think that a nonDTP quad mcpcb wouldn’t be able to take full advantage of a copper shell and would be better matched to a decent aluminum one.
Sandalian might have a point. When you look at the Sportac dropin’s
http://www.sportaclight.com/html/dropin_sf/features/index.html
you can see that the rearside of de dropin for Surefire (SF) differs from the dropin for (generic) 18650 hosts.
You can use an adapter ring http://www.nkon.nl/eagletac-flashlights/adapter-ring-for-surefire-dropins.html
Just my 2c.