My question relates to this panel, is there anything code or listing wise prohibiting using the main lugs of a panel where a backfed main has been installed, to subfeed another panel?
Since the breaker is bolt-on, any concerns about a retainer/ hold down bracket do not apply. Please forgive my cell phone pic & the pic will not display w/ the correct rotation.
From the 2011 NEC, 408.36(D). (F) in earlier editions.
(D) Back-Fed Devices. Plug-in-type overcurrent protection
devices or plug-in type main lug assemblies that are
backfed and used to terminate field-installed ungrounded
supply conductors shall be secured in place by an additional
fastener that requires other than a pull to release the
device from the mounting means on the panel.