yes, this is a nice tool. I’m just not sure if they ship an outdated evalglare version - make sure you replace it with the current one if so. The old version has some bugs in it and lesser safety tests (and is slower). The new version should be backwards-compatible.
Just two more notes: As far as I know the process there misses the projection-method adaptation, this you have to do separately.
As far as I know the average calculation of an area in that tool is based on average pixel-luminance and does not consider the difference in solid angle per pixel, which is necessary to conserve energy. For an angular projection method you can have a 20% deviation of the solid angle between pixels in the image - which means in worst case you end of with that deviation in your average luminance calculation. For typical images the error might be much smaller, but already having a vertical window where sou see partly a dark ground and in the upper part a bright sky, this can lead to a 5-10% deviation, which is an unnecessary add-on to the uncertainty that exists anyhow. So for a quick check that simplification is ok, but I would not use it in a scientific publication.