I think the whole bringing the steeped wort to a boil thing is to get it sufficiently warm enough for all of the DME/LME to get dissolved into solution. Too cool and it could just sink to the bottom and risk scalding.
This is just my logic......I'm sure someone more experienced will chime in.
Primary - Barleywine, APA, IPA, Strawberry, Pumpkin
Kegged - Raspberry Wheat
Bottled - Oatmeal Stout
On Deck -