UPDATE FROM MABULA
I have had a very rough 2 months unfortunately health wise. I was struck 3x in a row with bacterial infections. The second infection occurred  after a routine hospital checkup and I became very sick. I had to rest and take a lot of antibiotics. Once I was recovering and restarting work 1 month ago, I again became sick. The infection was not yet gone, so even more antibiotics and rest was needed. Needless to say, it took a lot of my energy and I needed a lot of rest.
Finally, the infection is really gone and my energy is coming back step-by-step now and I have started work again. I am terribly sorry to have kept you waiting for support. I will address all outstanding questions and e-mails step-by step and will be on the forum daily from today.
APP 2.0.0-beta47 will come soon as well, a lot of work was already completed before I became very ill, so the release is also nearly ready for you. Beta47 will be much faster actually. Many workflows will be more than 2x faster, mosaics can even be 10x faster than before because registration really received a major boost... all compared to beta46. Â Before I release it, I will make sure that everything is working properly and then I will release it.
Can I use APP to test what type of light filter (if any) will work best from my home backyard. E.g., if I take a blank shot and feed it to APP, it must know what light pollution is present in the image ( e.g., subtract the star light to get the background light). Could I use that information to identify what type of light filter if any could be used to remove some of the light pollution. May be the answer is no filter will work well but would like to know if there some objective way to come to this conclusion.
Good question. So, I think you can get an idea (never tested this like that myself), by looking at the SNR values etc. after processing. If you take a picture from the same object/part of the sky and in the same night compare the various filters (given the sky is at the same darkness level during that time), you may get an idea in that case.
