OB1
Jedi Master
Or it makes them actually useable?That trivializes utility spells almost as badly as this. There's little difference between 1 minutes at most and 9 minutes at most, and 3-5 minutes in most cases. If you don't have particularly tactically-minded casters, that's fine, but anyone smart will just never, ever, ever, memorize a utility spell again (or any healing or restoration spell that isn't Healing Word or Heal, basically).
I get where you are coming from, but the reality is, I can think of dozens of situations where you won't have a minute to spend before casting something. And even if you're right, that no one ever memorizes a utility spell again, I don't see what the problem is? Wizards have a big spell list and a book for a reason, guessing what will be useful for the day is unsatisfying, which is why I made the change years ago.