Consensus is just people agreeing on something. Science depends on tests passing, which does not depend on anyone agreeing on their results. Indeed, the point of tests is to remove the human from the 'equation' so to speak, therefore consensus isn't even possible.

If consensus is needed, it's probably because rigorous science cannot be done for whatever reason, like maybe not having enough fossil evidence.

not really , science is about building 100% bulletproof but falsifiable theories that are constantly being attacked by non-consenters and still win. No such thing as "fixed" scientific truth