Reaper7 unknowlingly provided me the missing link I've been searching for for maintaining speed and AOB when using the stadimeter with his work on trying to implement another way to do the stadimeter

You'll notice in the screenshots below that the speed and AOB dials have a red button attached to them. This red button 'sets' the speed or AOB in the TDC so that when you use the stadimeter it doesn't reset them to zero

. The whole thing is funky in how it works - Ubi really screwed everything up here.
So let's say you have a target locked. You determine it's AOB and set the AOB dial to what you calculated. Now you have to also press the AOB's red button to 'set' it into the TDC. Now you determine the target's speed and input that into the speed dial. Now you have to press the speed dial's red button to 'set' it into the TDC. Now you want to take a range reading. You click on stadimeter and determine the target's range. Now here's where things get funky - the values you 'set' are not reset to 0 - they persist BUT the AOB target value has been reset (Ubi bug

). What this means is if you mouse into the AOB dial then you will have to 'reset' the AOB to the correct value and press it's red button again to 'set' it (this is if manual input mode is enabled - if it's not enabled then mousing into the AOB dial will do nothing). Anytime you take a range reading it resets the AOB target value (this is a different value from the AOB dial's value).
Now I know someone is going to ask "Why can't it be automated?" Well the answer to that lies in the fact that I can't raise the button's click events (have tried) and I can't make the OnClick event handler fire for them either. If I could get one of them to work then there would be no need for the red buttons. Also, if I could find a way to set the TGT dials values then there would be no need for the red buttons. Once a way is found how to set dial's values (CrtVal, NewVal, etc.) it will open up a whole other level of modding SH5.
I'll write more about it and how it works tomorrow. I'm tired and wasn't going to bed until I figured this out