Singapore-Edmonton example, as brought by Sami (
https://www.airwaysim.com/forum/index.php/topic,82543.msg488649.html#msg488649), is indeed very interesting:
Only WSSS-CYEG and return is served, out of this city pair with only 4 possibilities (2 airports at each end).
Results from GW#4, 10 oct. 2031
WSSS-CYEG has actual at ~65% of potential (should be around 90%)
CYEG-WSSS has actual at ~90% of potential (seemingly correct)
WSSL-CYEG has actual at ~10% of potential (seemingly correct)
CYEG-WSSL has actual at ~70% of potential (impossible)
WSSS-CYXD has actual at ~10% of potential (seemingly correct)
CYXD-WSSS has actual at ~10% of potential (seemingly correct)
WSSL-CYXD has actual at ~10% of potential (seemingly correct)
CYXD-WSSL has actual at ~10% of potential (seemingly correct)
Seems pretty consistent with the result of my testing on the test server: SIN remains bugged just like before the fix, and then we can add the side effect of the fix. For what reason only SIN remains uncured while all other airports checked so far have only the side effect, I don't know.