Yep, the designer taking into account the strengths and limitations of the UI toolkit being used and remembering to design for more than just the happy path (e.

Yep, the designer taking into account the strengths and limitations of the UI toolkit being used and remembering to design for more than just the happy path (e.g. accounting for long strings and variable fonts) will get you 90% of the way. UIs localizing badly in my experience is often caused by rigid designs that make loads of assumptions and were only ever concerned with looking good in a mockup.