I choose a departure from leveraging the boot structure as the toe side base move. That move is often presented as "the" way to get on toe side, particularly by coaches who advocate more use of the upper body. In this maneuver the boot is bent to its limit and by using the boots structure the weight of the torso tips the board at the fulcrum (bypassing activity in the flexed ankle.)
Personally, I do not ride toe side turns in this manner. I argue that many riders who present this information as a "best practice" do not ride that way either. Often these are advanced riders. At complete collapse, the closed limit of the ankle joint, the associated muscles are less able to produce fine movements than when the ankle is flexed closer to its neutral position. I need to ride while writing this! I will check the following proposition today on the hill.
I propose the most powerful range of response for the ankle is that range which we use when we walk. Consider your ankle flex and its relationship to that range when you ride!
As an exercise to fine tune ankle movement for toe side (and heel side) turns take the board off. In a large open area (with good traction on your shoes) walk and run toe side and heel side turns. BE REAL! Go sideways, turn toe side and get on your toes while you do it. Its hard, mainly because we seldom actually walk sideways, but maintain the direction of your feet to be as they are when attached to your board.
The faster you "slide" sideways, the more you have to incline, angulate and flex your ankles. Without the snowboard boot structure, you can explore the range of motion in the ankle and its relation to centripetal force and their relation to inclination throughout various turn shapes and sizes and speeds.
When you go to the mountain, repeat the exercise inside before you boot up, again on the snow when you are booted and finally analyze your snowboarding toe side movements against those produced in my exercise. Try the movement range from the exercise in place of those your presently use.
Exceeding my standard walking range of flexion does happen when I err in my initial judgement and when I ride more challenging terrain. However, I when accurately used, this excessive range of motion in my ankle is mirrored by excessive flexion of my knee and hip. ie. my legs are very flexed then very extended. The useful range of motion in the ankle joint can be increased by repetitive practice. The ultimate outcome of a very flexed or very extended ankle on turns is a flatter board when more inclination is present. There is an obvious advantage to this in bumps and steeps.
It should be noted that inclination is controlled by the ankle joint and would therefore presume that the calf muscles must be able to support the full weight of everything above them plus the forces of the turn. It seems to me, this is most likely achieved if the muscles we call on during the turn to fine tune edge angles are closer to their "strongest" range. That range for me does not include fully flexed.