I have had a few bugs here and there (the delete button on the keyboard does work now in the manual tool where it would not work at first for example) and I realized that due to one of these glitches I don't fully understand the mask option in the training settings.
First, the guides say to always enable penalized mask loss and provides a good explanation. Next, if this is enabled you have to select a mask. I believe 'extended' is selected by default.
After that there is an option for "learn mask."
The guide says that "learn mask" will eat VRAM and may or may not help. The mask selected in training will be learned and can be applied at convert using the "preferred" mask setting.
If you choose a non landmarks based mask, all of your training data must have been extracted with the mask you selected in this section. If not the training program will not run until all of the offending images are removed.
What I don't understand is why there is an option to select a non landmarks based mask if you are only selecting the penalized loss function. It seems that there is nothing to gain and only something to loose.
Is there any benefit to selecting a mask other than components or extended unless you plan on using the learn mask feature for convert?