In this paper the authors have adapted a click chemistry-based method coupled with stimulated emission depletion nanoscopy (STED) to address these questions reporting that, in human cells in culture, the majority of mitochondrial protein synthesis is detected at the cristae membranes and is spatially separated from the sites of RNA processing and maturation.

(Deconvolved and rendered with Huygens – www.svi.nl)
Zorkau M., Albus C., Berlinguer-Palmini R., Chrzanowska-Lightowlers Z. & Lightowlers R.
High-resolution imaging reveals compartmentalization of mitochondrial protein synthesis in cultured human cells
PNAS February 9, 2021 118 (6) e2008778118;