For your info, 9889U has been back on revenue service. AEW5001 has
taken it, and I've seen it at St Teresa Church bus-stop towards AMK
at 1034am, although it seems like the bus has been doing different
shifts each day. I've spent 1 and a half hours waiting at AMK(8 am
to 930am) in the morning and 1 and a half hours at
Clementi(330pm to 5pm) in the afternoon when the "S" shift
normally starts but to no avail. Happy hunting for those who
wants to catch it. I'll update about the timings if I see it
again.
The problem with this S shift is that it can be easily taken over
by an amdep split shift bus. That's because both AM and PM peak
they start and end at AMK.