1) @supernov, well it could be done, but then you will need to select this before you start the process, otherwise APP will need to wait for your location confirmation before it can continue. I’ll think about this.
2) Letting the software choose where to place the area select boxes is the same as setting you up for a bad result. The sample problem for good gradient correction is extremely!!! difficult and fraud with danger. I have discussed this recently with Wei-Hao Wang (professional astrophysicist). Currently there is no robust answer to do this using an automated process. And since it is fraud with danger, I will not implement this, because chances are much bigger that the results will be worse.
Personally, placing 30 select boxes only takes a couple of minutes, so I don’t consider this a real problem. And it is virtually impossible to place the select boxes correctly all at once in images with a lof nebulosity, let alone automating it…. You need to study the gradients and work towards an optimal solution.
The gradient/light-pollution correction is usually done on a stack of multiple frames. The gradients in the data are extremely complex due to this and simply can’t be perfectly described by simpel models. So letting the software place select boxes in areas with similar values like for instance your first select box is really ill advised. It won’t help at all in my opinion (i have tested this thoroughly). It will only contribute to more errors and a less optimal model.
Saving such a model is really no solution, since no model will be the same. If you make a light frame of 5 minutes exposure time. Then another one of 5 minutes exposure time on any given night, the gradients will already be different. Combining the 2 lights will have another model, and so one…
I do understand your ideas and suggestions, but the problem of getting a good gradient correction is so complex that automating this, like you propose, will only give rise to less optimal solutions, so I don’t see much value for it.
Personally, I wish for the best solution, and this can be achieved with some experience using the interactive remove LP tool in APP. I will try to make a movie with sound showing you how to use this tool and how you can work towards an optimal solution.