Does efficiency suffer when brewing with flaked wheat or oats ?

Brewed a Wit today.

4# Pilsner
3# Belgian Wheat
2# Flaked Wheat
1# Flaked Oats

Was expecting to end up about .053 or better based on how my efficiency has been in the past, actually ended up with about .044. Truth is that probably works better for the kind of beer I'm trying to make anyway, but it raises some questions:

I was just wondering if this was something to be expected when brewing with that much wheat ?

I mashed for 90 minutes instead of 60 since I was expecting it to take a little longer due to the flaked wheat and oats. Maybe a little longer mash is in order next time ? Or is lower efficency just to be expected when brewing with this much non-enzyme adjuncts like Wheat and Oats ?

My efficiency was pretty high on a similar bill ~ 90%. I usually sit around 88%.

Batch Log

The only thing I did differently was that I step mashed with a 15 minute rest at 122F and ramp up to 158F. I don't know if that helped though.

How thick was the mash?
Did you do a single infusion or step mashing?
What about pH?

I believe Pilsner also has a lower DP than 2row. So that might require a longer mash given the ratio.

If the Belgian Wheat wasn't malted, you have a fairly heavy load for the Pilsner. I don't like to go over 1:1, 2-row to adjunct A step mash, as Bobby did is always a good idea with wheats.