Ending rail at Middle St or AMC makes  no difference to the commuter:  most commuters still have to catch  another bus to their final destinations.  Ala Moana Center is not a transit station, nor is it capable of moving riders where they want to go efficiently. Get over it as the end point.

The first 10 miles ends at Aloha Stadium.  The practical and best option is to convert the rail guide way to a 2-lane HOV(2) Reversible  freeway from Kapolei to Aloha Stadium for less than $4 Billion already collected via GET.  The two-lane reversible can be used for single passenger vehicles during non-peak hours.  Express buses can proceed beyond Aloha Stadium via H-1, Dillingham and Nimitz zipper to downtown, Waikiki, UH, Windward Oahu  and beyond with ease.

Tampa has built a Reversible Express Lane for $42 million per mile in year 2006, see   https://www.youtube.com/watch?v=LkM-MC3N-oY.  The Tampa elevated structure is built similar to the Oahu Rail guide  way.