Blitzcrank Targeting
I believe that changing the targeting system on Blitzcrank's pull to match Zephyr's targeting system would add a deeper layer of game play and allow Blitzcrank to better live up to the ideal of being a unique utility champion.
Currently Blitzcrank is limited in his ability to use his grab in a meaningful way throughout the game. During early game Blitzcrank shines as most players will prioritize high DPS units in the back lines with little ability to surround them due to the low number of units. As you move into mid game Blitzcrank usefulness is is situational as players avoid his pull by flanking priority units with with weaker units; Often Blitzcrank is naturally countered by people preparing for assassins. This is made worse as any scouting can allow players to adjust and counter Blitzcrank with little cost. In late game Blitzcrank will almost always be scouted leaving him as nothing more than a brawler or a cheese switch in.
By changing how Blitzcrank targets the game would get several benefits. The largest benefit would be an increase in the skill range of Blitzcrank: with the placement of Blitzcrank drastically affecting how the skill targets, you will allow a much deeper level of play where proper placement will make or break fights. This also will make Blitzcrank a much more interactive champion as he won't be ignored by all players after having low priority targets placed at the winds of a formation. Finally this would allow Blitzcrank to have use as a late game unit outside of niche cases.
I feel it is a wasted opportunity to have Blitzcrank remain as he is right now when a small change that already uses existing assets could allow him to fulfill his role while also adding depth to the game.