There is a lot of feedback available, and students are encouraged to upload videos for feedback and correction.
Given that SBL is a school, then the choice of material may also be a matter of finding decent teachers for a genre, rather than deliberately ignoring it. (My old school had a fantastic modern languages department, aparently, but couldn't offer Spanish).
There are a couple of courses on metal playing, one on prog metal, and some seminars. I'm sure Scott would love to find a thrash metal bassist prepared to write and teach a course on keeping that style and speed going for a full gig without injury.
Right - I'm off to practice the pieces "Abstract Noodle 6" and "Muddy Leeds River", followed by "Funky Love Glove"
See you in the shed when I've fixed the roof.