Brown Porter -- I want to use more brown malt

So, I've read a bit about people's brown porter recipes and there is a little divide between those who think there can be too much brown malt and those who like quite a bit of it. I'm inclined to go heavy but do not want to overdo it. I intend to enter a porter into a local comp this year and it's going to have to either be this one or possibly one I make based on my experience with this one so I need to get close with my first shot or else there's little chance the second shot will hit the bulls eye.

Here's my WIP recipe. Please help!

Recipe Specifications
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Boil Size: 13.00 gal
Post Boil Volume: 11.00 gal
Batch Size (fermenter): 10.50 gal
Bottling Volume: 10.00 gal
Estimated OG: 1.054 SG
Estimated Color: 21.2 SRM
Estimated IBU: 28.3 IBUs
Brewhouse Efficiency: 83.00 %
Est Mash Efficiency: 85.0 %
Boil Time: 60 Minutes

Ingredients:
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Amt Name Type # %/IBU
14 lbs Pale Malt, Maris Otter (3.0 SRM) Grain 1 73.7 %
2 lbs 8.0 oz Brown Malt (65.0 SRM) Grain 2 13.2 %
1 lbs Caramel/Crystal Malt - 60L (60.0 SRM) Grain 3 5.3 %
1 lbs Chocolate Malt (250.0 SRM) Grain 4 5.3 %
8.0 oz Acid Malt (3.0 SRM) Grain 5 2.6 %
0.75 oz Apollo [17.00 %] - Boil 60.0 min Hop 6 23.5 IBUs
2.00 oz Goldings, East Kent [3.60 %] - Boil 10.0 Hop 7 4.8 IBUs
1.0 pkg West Yorkshire Ale (Wyeast Labs #1469) [ Yeast 8 -


Mash Schedule: Single Infusion, Full Body, No Mash Out
Total Grain Weight: 19 lbs
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Name Description Step Temperat Step Time
Mash In Add 24.00 qt of water at 166.3 F 152.0 F 60 min

Sparge: Fly sparge with 9.48 gal water at 168.0 F

For my brown porter, I love brown malt! I use about 11% or so. I would increase the crystal/caramel malt a bit to balance the roastiness of the brown malt. The chocolate malt amount looks about right.

Why the acid malt? Do you need it for pH reasons? If you do, it's ok, but it's getting to the almost perceptibly tart level, and I don't think I'd like that in a brown porter.

I can't comment on the apollo hops, as I've never used them but I'd rather see "Englishy" hops in there if you could get them.

The acid malt is for pH. I've been advised the tartness is not perceptible up to and beyond 5%. Since I started adjusting mash pH with acid malt my efficiency jumped a couple points and my IPAs or other hoppy/bitter beers have more of a pop.

Apollo is supposed to provide a very clean and smooth bitterness. I could use EKG but what I have is 3.6% and it is my most used hops so I don't want to "waste" it for bittering.

I'll consider bumping the crystal a bit.

So you wouldn't advise I increase the Brown Malt to 4lbs, about 17% of the grist?

I like brown malt a lot and have used up to 15% in a Brown Porter but found it a bit much.
I have settled on 10%. Brew it with 13% then decide if you want slightly more or less next time.
It is a unique malt and can get some strange comments in comps from judges that have not used it or tasted it before.