Reach English C2 in writing and speaking within 18 months — single-language at a 'scientist' title in Germany caps the addressable employer pool at maybe 10% of what English unlocks and is the cheapest 10-point OVR move available.

Pick one concrete sub-specialty (ML/data engineering, computational biology, materials simulation — something the salary signal would actually reward) and ship a portfolio item or paper in it inside 6 months — converts generalist depth into the rare combination you've claimed but haven't shown.

Run a focused job search at name-brand employers in the same vertical with the new portfolio in hand — the current sub-median comp is the loudest evidence the seat is mispriced; a single market-test move would lift comp 30–50% and reset the scarcity signal.