How to fix creep block: Temporary Ghost Effect
To prevent situations where you're walled in by minions, the game should give you a temporary ghost effect so you can move out of them.
It would probably look something like "If you make contact with same minion for a constant 1.5 seconds, your champion will ignore minion collision for .75 seconds" This will make it so you don't have to waste flash in the event you're walled in by minions, but will still keep minion collision a thing.
You could probably add an internal cd to so nobody abuses it by standing on top of low health minions all the time.