If Kalista's Martial Poise is Such a Coding Nightmare, Why Keep It?
Kalista's passive gets a new bug every three patches or so, it seems. Being unable to cancel her autos is honestly not the best way to implement some kind of kiting mechanic. And a passive like that being intended to teach players how to orb walk doesn't really fit with a kit that has one of the most unique and complex kits in the class (Fate's Call doesn't seem like the type of ability that fits a player just learning how to ADC).
So why not move Martial Poise to just her Q, and give her a new passive so she can cancel her autos again and the people who like her don't have to sit around waiting on reworks and bug fixes?

etc
i count one. you're gonna need to help me with the rest.

speaking of bugs