Never heard ATC ask for 350 knts.
Understand your frustration, but such is life.
Its the disadvantage of props, dont go fast enough or high enough.
I have experienced the opposite , being asked to slow up behind
a turboprop 150 miles out and struggling to stay on schedule.
Although controlers may think it unnecessary, if possible explain
breifly what your intentions are. Unusually large speed changes make it hard to meet altitude constraints.
Stanstead controlers are great they never ask for speed change in the desent. Always when level.