Disagree with the default behaviour

It’s just my little opinion, but I think the plugin should make no changes until the user has requested it. I don’t think installing and activating the plugin to get to the settings page qualifies as requesting a change. I think the default post-activation behaviour should be to keep the wp-login name until such time as the user decides it shall be different, rather than choosing the name ‘login’ and implementing it immediately. The user can only access the settings page by activating the plugin, and an immediate login name change would affect everyone who logs in, even if they’re not ready.