The fact the oil consumption was ok before the timing belt and head gasket job would lead me to believe the turbo and pistons are reasonable - unless they were damaged by over heating due to your coolant loss?
My 184 is on 140k miles (225,000km) and i monitor my oil consumption. On average since 2022 is 0.12L per 1000km.
I think I would pull the injectors - and check to see if a particular cylinder is oily?
Obviously check all around the engine for external oil leaks? If nothing external - it must be burning the oil.