There are several chrome extensions that supposedly let you delay loading of choosen websites, but: 1. most of them have a google warning that they might be removed for "breaking the rules" 2. none of them work correctly. They don't block the first time you enter a website, and they don't block when you click links on the same domain. They work the best when you refresh, but even then - not always.
Similar extensions on firefox work perfectly. At this point I'm starting to get paranoid and think Google blocked this functionality on purpose (but then it wouldn't also be blocked for reddit and other websites so it's probably not on purpose).
List of extensions I've tried: one sec YouTube Detoxifier Delayed Gratification WaitBlock probably something else I forgot about
On the off chance this is done on purpose I switched back to firefox cause if true it's outrageous.
The pro version could also provide you the delayed launch that you asked for.
Blocking/routing is harder and less configurable in Manifest V3