I've never had to use teams over multiple organisations, but I do remember that it did not support multi-account until much further down the road.
I think if I had to use teams on multiple accounts simultaneously, I would have loaded the web app in separate firefox multi-account containers. (I do that at home to keep all of my work and home accounts separate and it works like a dream. It's probably the one feature you can show to get people to switch away from chrome when you show it to them.)
I'm unaware of the bandwidth usage on MacOS & Windows since I've always just used the building's connection. Teams on my Android phone hasn't seemed to cause any bandwidth issues though.
I think if I had to use teams on multiple accounts simultaneously, I would have loaded the web app in separate firefox multi-account containers. (I do that at home to keep all of my work and home accounts separate and it works like a dream. It's probably the one feature you can show to get people to switch away from chrome when you show it to them.)
I'm unaware of the bandwidth usage on MacOS & Windows since I've always just used the building's connection. Teams on my Android phone hasn't seemed to cause any bandwidth issues though.