The POLAR-2 instrument is a space-based X-/gamma-ray polarimeter which will be launched in Spring 2025. The instrument is being developed by a Swiss, Polish, German and Chinese collaboration. It will perform polarization measurements of photons coming from a range of astrophysical sources. To perform such measurements it is of crucial importance to study the performance of the instrument prior to launch using a dedicated polarized beam. For this, X-rays at different energies from a well-controlled beam are required. The ESRF facility therefore forms the ideal location to verify the POLAR-2 detector concept. Measurements will be performed on the final prototype of POLAR-2 for a range of different energies and instrument configurations in order to gain a full understanding of the detector performance. The results of this study will form the basis of one scientific publication, whereas further lessons learned from this study can still be implemented in the final detector design.