Splitting Grains

I am going to be brewing an extract Wheat beer with some steeping (Mini mashed) grains this next weekend.

After reading how a lower temp Mash will cause less flavors from the grains to be present and produce a drier beer and higher temp will produce more flavors from the grain to remain, I had a thought. I wanted to solicit comments on splitting the grain bag and doing half at 148* and half at 158*.

Here is what I have so far.
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6 lbs. wheat LME
1/2 lb. wheat malt grain
1/2 lb. two-row pale malt grain
1/4 lb. crystal 10L malt grain
1/2 lb. Flaked wheat
[All the grains (except the Crystal 10L) for this batch are already mixed in one bag from the LHBS.]

I was thinking I should shoot for the higher temp with it all because it is a Wheat Beer and you want a lot of these flavors present.

Any thoughts or comments on doing this with this brew or some other brew that might benefit from this practice?

Mash temperature doesn't really effect flavor as much as fermentability. Lower temperatures favor smaller chain sugars, while higher temps favor longer chain sugars and dextrins. Since the bulk of your fermentables are coming from extract, it's really not worth it. Mash it at 154 and call it done.