In my experience, it's OK to have a (slightly) longer load time for content behind a login wall. I also spend extra effort caching whatever I can for return visits. Refreshing the page should give you an almost instant load time.
Yea, I've run user feedback sessions. Page loads never come up as a complaint (plenty of other things to complain about :P)
The goal was to keep an average of <3.0s for the first meaningful paint, after login. Before login, all pages were treated with the same respect you'd treat any marketing page; render what you can as fast as you can.
Back with AngularJS, when code-splitting and lazy-loading modules/controllers wasn't an option, you had to get creative. Since moving to Vue, initial page load has never been an issue.
