I used it a long time ago (like 2017) and saved me some good money, but I also did not use my skymiles account just in case.
I felt like it got less effective at finding the types of flights like the one I took and stopped trying.
It's definitely a bit of a pain because you gotta book two one-way flights
Same, we were sharing with my father-in-law who lives like 10min from here, and he was cut off.