The Brightline extension might have required only 28 miles of new ROW, but it also entailed extensive additional trackage, new bridges and grade crossing improvements in the stretch from West Palm to Cocoa. BLW, by comparison, has fewer grade crossings, and the rivers it will need to bridge have no boating interests since they only intermittently contain water. So while it contains a lot more track, I have a hunch that in all it's a simpler project.
When I looked at the latest Metrolink map, I saw that there is, in fact, an existing shuttle service from RC to ONT; the schedule has it making the connection in c. 15-20 minutes. So that apparently already exists, but I am not sure how valuable it is in relation to BLW except possibly for people coming from the other two California stops.
"...And then I thought, every time some company creates a more powerful locomotive does Superman become more powerful as well or is he stuck at 1938 locomotive power levels?" - A friend of mine elsewhere
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