Join Date: May 2004
Location: SIN (LEJ once a year)
Programs: SQ, LH, BA, IHG Diamond AMB, HH Gold, SLH Indulged, Accor Gold, Hyatt Discoverist
Posts: 8,817
Just as a data point, flying to and from NRT on SQ 638/37 on B787 and was also able to select 11D/F either during booking or later on while doing a "routine" seat map check. YMMV.