A normal person would immediately think "dang, page didn't load before I entered the tunnel. Guess I'll wait til I'm out again and refresh".
And if they're deliberately going somewhwre where there's no signal for an extended period of time, and really want it to work, they'll ensure they've loaded everything before doing so.
And I say this as someone who is developing a pwa that is for people with low end phones and very inconsistent and/or connections. I'm very cognizant and empathetic to their situation.
Anecdotal evidence does not beat statistics and user research. Bounce rate has inverse correlation to loading speed. People with low intent do not refresh, they simply don‘t come back and look elsewhere or just move on. Telling you this as someone who built first commercial website in 1999 and was a hyperscaler B2C startup CTO. Let‘s not measure the length of credentials.