Non-SRFI 198:

PC-Scheme for DOS: interesting trivia (I bought a copy back then), not an issue for SRFI 170 finalization.

fdes and port: Still unresolved, and I believe unresolvable, see https://srfi-email.schemers.org/srfi-170/msg/15008762/; Shiro's last reply did not get addressed.

monotonic-time and timespec: Perhaps unresolved, here's the discussion thread: https://srfi-email.schemers.org/srfi-170/msg/15051189/