User blog comment:Supp0rt4n00bz/What if summoner spells can be changed in-game?/@comment-5266525-20130827170458

I'm unsure of the benefits it would have. The long cooldown of summoner spells makes it completely impossible to utilise the feature for tactical purposes, and anything long-term you have in mind can almost always just decide your spells at champion select. Only case I think it could make a difference is when the game has gone very one-sidedly and you change your summoners to less/more offensive ones to deal with it.