Cut and cover for the tunnel entrance, partial for Nanwood, and TBM the rest of the way. Two if they somehow explain how they're going to get another one on the opposite side.
From what I understand, the underground station design still has to be done. In the documented I provided earlier, it showed the station design below downtown Brampton GO with one LRV on each side, so it has be thinking it'd be something similar to the subway lines you see in Toronto.
Cut and cover isn't for the entirety of the route, just for the tunnel entrance with partial on Nanwood. Any option provided for the Brampton extension at this point would be a waste of money because only Mississauga received funding for their portion. The Mississauga Loop was in the initial design, then removed, then added again as part of phase two. One could argue that the loop was re-added to buy votes and seats as well. Whether or not you agree with it, Mississauga has to contend with the same issues that Brampton does when it comes to getting things done by the current government. But that's neither here nor there for discussion.
Median on Main or diversion to Kennedy were already discussed nearly over a decade ago. When the initial conversation about having a LRT in Brampton was announced, there were NIMBY's who lived right along the Main Street corridor who opposed the idea of it strongly. So strongly that you had factions in Brampton City Hall who were vetoing ever building it along Main Street in support of those NIMBY's, and instead suggesting Kennedy Road. McLaughlin, diversions along other inner streets, and other routes that I don't even remember anymore. Not to mention, diverting along those routes does nothing to solve the influx of people coming off the GO train, Go Bus, or arriving by bus to downtown Brampton.
They suggested these routes because they didn't want to lose their long driveway ROW, and were more concerned about their property values than they were about ever using it as a service. They thought that the sight of an above ground LRT was absolutely heinous, and would cause traffic disruptions and so on. This stalled the development in Brampton, and it only recently started back up once the vetoing faction was voted out. None of their suggestions had anything to do with ever running the LRT into downtown Brampton.
Whether or not you agree with the line being done the way it is, comparing Brampton's downtown to Mississauga's City Centre without focusing on the stops in between, or additional variables means you're focusing on only one section of the entirety of the HMLRT. The 502 that travels on Main starts from Hurontario / Sandalwood, makes a few stops before hitting Downtown Brampton, makes a few stops before hitting Gateway Terminal, and then a few stops in Mississauga before hitting Square One. By one point, the bus is already full, and some stops have been skipped because of how full the bus is, and how many people are not getting off because they're all trying to go to Square One. Combine this with the fact that it's rush hour, Main/Theatre, Main/Queen, Main/Welington are completely backed up. People are waiting for a bus to come because the other buses are full. The bus takes longer than the scheduled time because of gridlock.
The tunnel for the LRT will reallocate resources from Brampton Transit's 502 to the incoming 504, and eventually the currently being planned 515, while also ensuring that everyone is able to get on, and be moved around the city to where they need to get to.
Also... I'd like to know what historical significance a shopping mall has when we're talking about moving a significant number of people via different transit solutions between one city to another city. Heritage is one thing, but to suggest that a city must have heritage in order to benefit from something is a little.... Strange to me I suppose.