declarativeNetRequest type redirect unreliable in Safari

[ACTCD]

Problems may manifest as but are not limited to:

• In some scenarios, the tab is remains in the loading state (the progress bar of the address bar is stuck)
• Sometimes, the tab behaves like the navigation action is cancelled. (Progress bar disappears but remains on previous page)
• Redirection is successful but prompts "This web page was reloaded because a problem occurred." (#491)

A simple DNR rule is used to test:

{
	"id": 12345,
	"condition": {
		"requestDomains": ["example.com"],
		"resourceTypes": ["main_frame"]
	},
	"action": {
		"type": "redirect",
		"redirect": {
			"url": "https://example.org/redirected"
		}
	}
}

When typing example.com directly in address bar of a new tab or a existing tab, or opening https://example.com/ in the current window or new tab by clicking (or command-click) on a anchor pointing to it, you may find that the redirect is successful in some cases and not in others.

This uncertainty is difficult to debug, it has nothing to do with the rule itself and appears to be some issues with Safari's internal processing.