There are semi private trackers out there that you can get an invite fairly easy, as do open signups pretty often.
You don’t need to think about it too much, as most 4K content usually crosses the trigger for freeleech. That means you are fine as long as you don’t do a Hit ’n Run, which in itself is an asshole thing to do.
I have a fully automated system and don’t even bother checking where I am downloading from, or what my ratios are, all is taken care in the background.