What should be checked first for feat use:
FEAT_IMPROVED_KNOCKDOWN (17)
What is likely checked first:
FEAT_KNOCKDOWN (23)
This thread will be something I revisit with summons that I can test and access as individual posts that do not correctly use their kd feats. I encourage others to add to this for completions sake.
How it should look:
Knockdown only:


Improved Knockdown:


Summary of testing so far:
Summons that have both knockdown feat and Improved knockdown feat will always default to knockdown, regardless of intelligence status.
Summons that only have improved knockdown feat but not the intelligence can't use it.
Not a single improved knockdown capable summon tested actually uses improved knockdown.
Gold dragon is more difficult to test but I am working on having someone help there.
Still needs testing:
Dragonknight - Gold Dragon.