If I understand correctly, the problem with thinking about the 7th mode of Ab melodic minor is that it doesn't tell you what the functions of those notes are over G7. It tells you how to run up and down the scale, but that may not be the best way to use that sound.
I think of it this way. We practice scales till they are memorized, and then we keep repeating them until they are "under our fingers" which means we can play them up and down without thinking. The other thing that happens is that we get the sound of that scale in our head. All of those notes under our fingers and sounds in our head can be drawn upon when we improvise.
It is not complicated. All of the "altered" notes of the altered scale (super locrian) b9, #9, b5, #5, b7 have the
same function. That is to add color and tension over the V7 that is then released when the chord resolves to the tonic. For me practicing the Ab major scale, then the Ab major scale with a lowered 3rd, then running that same scale from ti to ti instead of do to do is simply a shortcut to quickly get that note pattern under my fingers and the sound of that scale inside my head.
Edit:
My post about how I think about the "altered scale" is not meant to suggest that I would use that sound in a traditional blues which is related to the topic of this thread. Depending upon the melody and tempo the notes of the "altered scale" may work in a jazz blues setting over the V7.
