@Gnopps I can imagine that implementing your suggestion would be slightly longer than my suggestion of a swift hotkey into a field(!) but yes, that I would vote for that too - in fact I just have!
Interestingly MLO (where I have been living for many months) has something similar to Gnopps's suggestion and although it does sound like a fantastic idea, interestingly enough, I don't tend to use much on MLO. The reason is because MLO will automatically default in any tags that the parent currently has at the time you create any child task, and this saves both time and mental energy.
To be honest, the fact that GTDNext fails to do this as well is potentially quite a serious omission - or it certainly would be if you were trying to use tags for anything beyond real-world Context (as I keep finding myself being forced to in MLO).
Fwiw, I have been living on MLO for over a year and mad as it sounds, right now I am currently living on both MLO and GTDNext.com. MLO is an extremely mature product and although overall the interface seems cluttered & confusing, MLO has a superb extremely slick user interface in other very specific ways. In short, in my humble opinion, GTDNext does have a vast amount to learn to from MLO.
However unfortunately for MLO, unlike GTDNext, MLO has no separate database fields for either 'Area of Life' or 'List' and as a result after much experimentation, I finally have been forced to use tags to store data for both these fields, which is frankly yes, bonkers. And this is precisely where GTDNext scores... And is precisely why I am here.