I don't see why that would affect it, unless that Back button press modifies the URL such that it is out of the current live session, which would trigger a page reload.
My LiveView is rusty, but I encourage you to reconfirm your assumptions, as I think that things work the way we both hope they do (as long as the live session doesn't change).
I don't think that has to be the case. You can use "patch" style links to navigate from page to page in the same session.
https://hexdocs.pm/phoenix_live_view/live-navigation.html