I've found this works really well for me when using the Littlebirds. I'm not sure how it would fit into your situation though...sounds like you may have tried this already anyway.
I place a WP right befor the Land WP and I set the speed to "Limited", the combat mode to "careless" and set the height (again) to whatever I want.
I then make the land WP with the same speed and combat mode, then a 3rd WP after the land WP and set the speed, combat mode, and height back to normal.
I'm not the brightest bulb so I think of it like this: one WP to slow her down, remove the fraction of intelligence the AI has, and set the height.
One WP to Land the bird.
Then a 3rd WP to bring everything back to normal.
Honestly, I haven't had any problems with this method (unless the H pad is blocked by something(one))
;D
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