Extension to Boon Lay is way too far, making the new route 36km
in one direction and prone to delays / bunching. Along with the
different loading pattern on both sides, not worth it.
CCK maybe, but there would be a duplication of route (190) to
Orchard. Also provided that there's space, which doesn't seem so at
the moment. (Unless ... we can move some CCK services to Gali Batu
or Bt Batok, then possible)
My preference has always been CCK but there is space constraint,
unless 172 can be made Boon Lay <> CCK (loop) to accommodate
700.
It won't duplicate 190 at all except for starting point as 700
will use Keat Hong to reach BPJ while 190 uses Teck Whye. Given how
popular 190 is from Teck Whye to Whitley-Orchard, I assume 700 will
be v popular too.