WHBM.
You are correct regarding the additional places served.
We also did Lhr - Bos - Phl and return.
The direct LAX was usually doable but often, if it was tight, reduced contingency was utilised.
For those that don't know, this allows for the reduction of contingency fuel (figure escapes me but it was % of the total fuel required from dep to dest to alt) by nominating an en route alternate.
Thus the contingency required can be reduced as the total distance is reduced.
As one got nearer the destination the remaining required contingency, assuming it has not been used, reduces as the distance to destination has reduced.
So one may fuel plan, for example, lhr - Winnipeg - lax and as one got nearer to Winnipeg replan to las -lax and then nearer las replan to lax with Ontario (California) as diversion.
A long time ago but I think I've got it about right.
The sector was tight for crew hours and a standby crew, the next day's operating crew, was stationed in a local hotel, waiting like coiled springs, lest the operation was delayed.
Again, a long time ago, but I think we were stood down, from standby, when the aircraft had passed the mid atlantic point.