Yikes, this is indeed a tall order with alu; apart from anything else, the degree of temper drifts with time.
If this is a recurrent job, you'll probably need to either make the die adjustable if possible, or shop around (make test coupons and a simple portable tester for springback so you can qualify material at source)
The only other things you could do are 'iron' the bend area, which takes strong tooling and lots of tonnage, or use a tangential/ stretch tool of some sort (If it's a 2D bend)
Possibly if it's a 3D bend you could grip the blank on all sides and apply multidirectional pre-tension prior to (and during) forming, but it would be tricky to avoid Luders lines.