Right, only had a a brief play, but first impressions count for a lot. The new fixed aim while shooting diagonally works tremendously well, almost a master-stroke. However, let's go for perfection and at the moment I can see a few flaws. For one, the new fixed aim implementation is so good that I'm really not even sure you need the contextual sloping angle shooting any more. Indeed I find its presence more annoying rather than helpful (using a joypad at least). Especially for situations like my first screenshot.
Notice all I really want to do is shoot horizontally over the top of the hill, but in order to do so I have to press down, this just feels weird. When standing on a down-slope you have to press down to shoot diagonally whereas when standing on an up-slope shooting diagonally is automatic. Having two different mechanisms for different types of slopes feels bizarre. When standing on an up-slope horizontal shooting should persist and the player should have to press up to aim diagonally along the slope to in order mirror the behaviour of the down-slope controls. It does not matter that for the most part there is no reason to shoot horizontally on an up-slope, the beauty in the symmetry of the controls is more important.
One major problem I can see with the new fixed diagonal shooting is that you don't seem to be able to shoot down diagonally, which seems like a massive oversight. Check my second screenshot. I'm trying to shoot at the windmill down diagonally, but I just can't do it. There is no reason for this. The crouching shot can still be performed by pressing directly down, so I should be able to shoot diagonally by pressing diagonal buttons.
The third point is just an aesthetic one. Aiming back behind you without specific extra animation frames seems a little strange. It's like you're shooting out of the back of your head or something. Don't see why you can't just let the character turn around.
That's all for now. I really like the fixed diagonal shooting mechanic, great work! But please, don't stop now, refine these controls as much as possible to get them absolutely perfect. It will pay off greatly in the long run.