> LM on untreated copper (which I thought wasn't really advised).

I think the supposed issue is nickel (the most common waterblock coating) has a much lower thermal conductivity so you might lose a degree or two under load vs a bare copper block.

Which kind of makes sense: people who know what they're doing use liquid metal to squeeze out that last couple degrees vs PTM/graphene so going bare copper and dealing the the buildup problems maybe makes sense for them too.

He mentions in this video that liquid metal really should just be for the extreme overclockers who don't mind changing it out and resurfacing their waterblocks regularly which is good advice. The fact liquid metal is even semi-mainstream and comes standard on any consumer hardware is kind of stupid.