You should try out the pre-release
 https://github.com/rordenlab/MRIcroGL/releases/tag/v1.2.20210624
this includes a new feature
 https://github.com/rordenlab/MRIcroGL/issues/22
specifically, choose View/Multiplanar(A+C+S+R) to see four views simultaneously: the axial, coronal, sagittal and rendering. Clicking on the rendering will show you the corresponding location on the 2D slices.