It is possible that specs may have called out insulating bushings with a 150°C rating as opposed to 105°C, and all that was reasonably available meeting that spec were metal bushings with nonmetallic-insulating inserts. [150°C parts are less susceptible to damage/cut-through by smaller-diameter rope/line during cable pulling.] Or—they could have been ‘surplus’ from another job.
On the lopped-off 1/0s, there may be objections to abandoned conductors left in new work.
