My tutorial differs from the youtube guide because i have found that with that method (on the video) it can effect how positive the small ring trim feels at the lever and trying to re-adjust the tension via the barrel adjuster only then prevents the big ring trim from working correctly.

My guide method is a trade off, it will eliminate the big ring trim in favour for a better small ring trim. Which i believe is more useful. Though depending on your frame and chainline you may not need the big ring trim at all.

If you need the big ring trim, and you'd want big/big as an option.

The youtube guide is probably the best guide to use.

Whichever works best on your set up is up to you.