This might help, although somewhat technical.

https://developer.mozilla.org/en-US/docs/Web/HTTP/Redirections

The above seems to refer to redirection of individual pages of web sites doing their own maintenance, moving pages, for updates, and other reasons detailed and stated in the above url explanation.

The question that seemed unanswered is:

Can a redirection as "allowed" by Firefox when selected take the user to an unwanted and UNEXPECTED site? That is, malware or unwanted/un-requested advertising, or any "crimeware" location?

The question is still open: How can a Firefox user see the URL of the redirect before selecting 'allow'.

Hope this helps.

Thank you. NR Washington DC

There are some add-ons that can 'clean' redirects.

Go to the Mozilla Add-ons Web Page {web link} (There’s a lot of good stuff here) and search for what you want.

Thank you.

Using REDIRECT CONTROL allows viewing the urls.

Seems to work well with Windows 10 and latest firefox.

Replaces the firefox redirect "bar" with a similar bar listing site information and options to allow etc.

Thanks

That was very good work. Well done. Please flag your last post as Solved Problem so others will know.