I've been watching some light rail cab ride videos on YT, and man I want a light rail route in NYC so badly haha.
North Shore/West Shore light rail in Staten Island is the best bet, there's space for it and there could be a mix of street running and running on it's own ROW. Anything else is a pipe dream IMO.
As much as I love for the Bay Ridge branch to become an light rail, it IS an active freight line and you can't just tell NY & Atlantic railway to go f***k themselves so the MTA can have the ROW to themselves. IDK if there's enough space on the ROW for an isolated freight track and two LR tracks and an Island platform for stations.
The Triboro RX as an light rail would have to terminate in Fresh Pond or Jackson Heights as sending it to the BX along with Metro North penn station access already being on that row there's no way there's space for all that.
I already have the vision of how the MTA light rail vehicles would look like... MTA light rail signs on the side like how our subway cars say MTA NYC Subway on the side, same countdown clocks that are in B div stations, FIND on the light rail trains themselves and wrapped in the same Cuomo scheme the buses are... Talk to text automated announcements to announce the stops.