Roeselare in Brown ale?

This is a surly bender clone and was thinking about spitting it and pitching half with the Wyeast Roeselare ale blend after primary is complete.  I have never done a sour but have had a sour brown and it was tasty. Any suggestions on the process/how to or a different yeast?

—RECIPE SPECIFICATIONS-----------------------------------------------
SRM: 19.9 SRM SRM RANGE: 18.0-35.0 SRM
IBU: 26.8 IBUs Tinseth IBU RANGE: 20.0-40.0 IBUs
OG: 1.056 SG OG RANGE: 1.045-1.060 SG
FG: 1.014 SG FG RANGE: 1.010-1.016 SG
BU:GU: 0.479 Calories: 151.6 kcal/12oz Est ABV: 5.5 %
EE%: 72.00 % Batch: 5.50 gal      Boil: 8.60 gal BT: 60 Mins

—WATER CHEMISTRY ADDITIONS----------------

Total Grain Weight: 12 lbs 0.9 oz Total Hops: 3.50 oz oz.
—MASH/STEEP PROCESS------MASH PH:5.50 ------

-ADD WATER CHEMICALS BEFORE GRAINS!!<<<<<<<
Amt                  Name                                    Type          #        %/IBU       
7 lbs 11.3 oz        Pale Malt (2 Row) US (2.0 SRM)          Grain        1        64.0 %       
1 lbs 14.8 oz        Aromatic Malt (26.0 SRM)                Grain        2        16.0 %       
11.6 oz              Crystal, Medium (Simpsons) (55.0 SRM)    Grain        3        6.0 %       
11.6 oz              Oats, Golden Naked (Simpsons) (10.0 SRM) Grain        4        6.0 %       
11.6 oz              Special B Malt (180.0 SRM)              Grain        5        6.0 %       
4.0 oz                Chocolate (Briess) (342.0 SRM)          Grain        6        2.1 %

Name              Description                            Step Temperat Step Time   
Mash In          Add 5.46 gal of water at 164.8 F        154.0 F      60 min

—SPARGE PROCESS—

-RECYCLE FIRST RUNNINGS & VERIFY GRAIN/MLT TEMPS: 65.0 F/68.0 F
-ADD BOIL CHEMICALS BEFORE FWH
Fly sparge with 4.77 gal water at 168.0 F
Amt                  Name                                    Type          #        %/IBU       
0.50 oz              Willamette [6.50 %] - First Wort 60.0 mi Hop          7        9.1 IBUs

—BOIL PROCESS-----------------------------
Est Pre_Boil Gravity: 1.049 SG Est OG: 1.056 SG
Amt                  Name                                    Type          #        %/IBU       
0.50 oz              Columbus (Tomahawk) [13.90 %] - Boil 60. Hop          8        17.7 IBUs

Amt                  Name                                    Type          #        %/IBU       
2.50 oz              Willamette [5.50 %] - Aroma Steep 0.0 mi Hop          9        0.0 IBUs

—FERM PROCESS-----------------------------

Strictly my opinion, but late addition hops and sours don’t go well together.  Otherwise I think it’s a great idea.  A friend brought a keg of under attenuated porter to a party last year and nobody drank it so I racked it back to a carboy and added bottle dregs from a wide variety of sours and brett beers.  It turned out delicious and only took a few months.

I agree with what corky said, and also, I believe this is overly bitter for a sour. I usually bitter to about 10IBU, all at 60 (usually about 1/4oz of magnum @60 iirc). The grain bill seems fine for a sour (Flanders) brown. You may want to add some flour (1/4 cup or so) to the boil. I read somewhere (I want to say Raj Apte’s essay) that starches help force the brett and lacto to wake up and produce a bit more acidity. I can confirm that they do break down the starch, and there is no haze.

Re Yeast: the Roselare blend is a pretty tasty blend, but it definitely takes a while. I have a flanders red that is a year old and is just getting ready to go into the keg. I have heard that the 2nd and 3rd generations are quicker to sour.

Those are my 2 cents.

Doesn’t seem to be all that bitter, and with a long secondary the bitterness might subside a little.  Roeselare added after primary probably won’t get real sour, might make a fine Flanders brown though.