Quite possible, however I managed to dirty edit my save file to increase bandwith in a specific region, as soon as I went up a porter level it reset to what it should be.
And like you I had a good look, knowing what I know above, I was looking for some math/s for the porter level that affects the bandwith #, couldn't find it.
I might look later.
EDIT: Brain Wave happened, why max it when you can set the current used total to 0?
[Edited by DABhand, 7/15/2020 3:11:18 AM]