You don't have to wait for them to enable it for everyone. Enable it yourself by setting browser.tabs.remote.autostart to true in about:config (on ff48-53 this'll use one one process for ui and one for all tabs, I believe on 54+ it'll use more). (As long as you don't have any addons that don't support it, anyway -- after enabling it, check in about:support under "Multiprocess Windows", and if not, about:addons should show the offending addon. IIRC there's a staged rollout, so it may already be enabled for you even if you don't force it on, unless you have an addon that doesn't support it)