How likely is a supersized mammal given 150 million years?

I'm just wondering, since this sub is about speculative evolution, how likely would a truly large mammal be if humans never existed and mammals were allowed to continue developing unchanged like the dinosaurs were?

Do you think that something larger than paleoloxodon would eventually emerge, or is that the size limit in your opinion?

What about the mammalian carnivores? Do you think that arctotherium is the largest that a mammalian predator could get?

Personally, I think that something larger than paleoloxodon would emerge, given that the overall structure could just be supersized a tiny bit more, and maybe the trunk elongated to scoop up leaves from trees.

As for the carnivores, I think that largest one would be around 2-4 tonnes and not get much larger due to mammalian tendency for pack hunting.

What are your guys' thoughts on this?