I daily drive FF Focus. When I encounter the discussed page, I just navigate to 'Open in..." and choose my TOR browser and open it there. VPN stays active all the time (Proton).
I'll check if it loads the page as an onion site or not.
..
Checked, loaded with default settings (.com) and as an .onion site. Both work.
The Tor Browser has this setting to redirect clearweb urls to onion urls.
When used in the Tor browser, I can access reddit with it's clearweb site (.com) and (with the "prioritize Tor sites" turned on) the url showing it as onion site (.onion).
Hope I understand it right and with the setting turned on, tor indeed "magically makes clear web site to an onion site".