CGK-SIN-NRT-JFK-FRA-(extra europe?)-TLV-FRA-SIN-CGK gives 25,080 miles and several good longhaul F options
SIN-NRT SQ (744)
NRT-JFK NH
JFK-FRA SQ (744) for access to VS clubhouse or LH for access to FCL on arrival
FRA-TLV-FRA LH
FRA-SIN LH for FCT or SQ for 77W
there is significant extra mileage for intra-europe or intra-asia (eg return via NRT)