[also a CS 343 TA] I personally agree with you -- if it were up to me I'd refactor CS 343 into a pair of courses, maybe focusing on high-level concurrency constructs with a follow-up course on building that sort of runtime system.

I personally really hated the use of uC++ and would have loved to do the whole course in some MIPS dialect. I really liked how through most of second year the only language reference I really needed to look at fit on one piece of paper (https://www.student.cs.uwaterloo.ca/~cs241/mips/mipsref.pdf). The uC++ language, on the other hand, is not specified anywhere except in the enormous 600 page textbook, and even then very far from fully specified (e.g. there was a builtin function called rendezvous-something, where that string literally only appeared in the book once, and it was not defined at that place)

I'd argue that's the point of moving from a 2nd year course to a 3rd year one. You incrementally add more complexity. The ISO C++ spec is a similar heavy tome.