P: Generate mask from Blend If

In blend if masking, once I set it to what I like, or what is only available, I'm done, that's it.
Well, I'm saying no. I'm saying, I like that, I want to keep it, I may want to add to it, some other aspect of the effects, or parts of the whole image through it all on the spot. Holding on to all of the best parts of Blend if, before making my final commitment. Blend If has too much to offer, to not offer more.

A light dark select capture lock grabber, while still capable of further fluctuations. Photoshop's own Flux Capacitor, I'm not trying to be funny either.

As you said, Blend If is a dynamic mask, that's why it should be made more dynamic, instead of partially dynamic. With the user having more variables to work with.

Before making the commitment to leave Blend If, there's an in-between stage, which would be like having another middle slider between the two, which is assigned to a mask, or kinda a safety layer inside of Blend If, so that, when I say wow, look at that effect, I can save it and still move on to capture other effects the blend if offers, or cut out through the mask territories I wish to maintain from either the 'this layer' or the layer 'underlying layer', like a capture device of the best part of each layer holding bits of the original of each you want shown, with the capability of still adjusting within that the blend mode and opacity.In other words, of my two image layers, I not only can use Blend If, I can composite control between these two as well, bringing both of the layers potential magic when mixed.
This is separate from using just layer masks on each image, and Blend If on the two layers each one having a layer mask attached, because, you want to see your work as it happens right before your eyes, as you make your adjustments.
That was a bit long winded, but I know I'm on to something that can be figured out, to enhance Blend If even further. I have no screenshots to fully express what I'm talking about. Sometimes, a never been done before idea, is just that, an idea to be considered, at first thought crazy, and later thought, oh. yeah!

I don’t understand the suggestion either. Blend if is a dynamic mask, in contrast to normal masks. The mask changes automatically when you change the content of the layer(s). Add a normal layer mask if you want to make local changes.

I'm a little confused. Blend If is creating a mask, even though we don't see it and can't access it like a pixel mask. Are you asking for that mask to be displayed in a pixel layer? Or are you asking to be able to use a mask you've already created to mask the blend if mask and if so, can you give me an example in a screenshot or something?  I'm all for Blend If to be more versatile and simple. I just don't appear to have the imagination to understand what you're asking for.