rel="ugc" vs rel="ugc,nofollow"

[Dani]

According to this page we switched links within our forum posts from using rel="nofollow" to rel="ugc". However, Do you think that it makes sense to use rel="nofollow,ugc", or is the nofollow part already implied? Does anyone have any anecdotal evidence as to whether they've noticed a real world difference between the two?

[pritaeas]

According to: https://developers.google.com/search/blog/2019/09/evolving-nofollow-new-ways-to-identify

Can I use more than one rel value on a link?
Yes, you can use more than one rel value on a link. For example, rel="ugc sponsored" is a perfectly valid attribute which hints that the link came from user-generated content and is sponsored. It's also valid to use nofollow with the new attributes—such as rel="nofollow ugc"—if you wish to be backwards-compatible with services that don't support the new attributes.

So it only says you can. Other than that, no real explanation found on using the two together.

[Dani]

Yes but this is the SEO industry! That means you can’t just go off official Google guidance because Google doesn’t disclose what works best in their algorithms. Real world SEOs do A/B tests to see which actually gets better results, and then shares those results with the SEO community. I was just curious if any of that information was out there for this yet.

[Dani]

… other than, of course, knowing Google treats nofollow as a hint now as opposed to a directive, as it used to.

[Dani]

So it only says you can. Other than that, no real explanation found on using the two together.

That's why I asked in my question if anyone has any anecdotal evidence. ;)