Jaffa Brew?

[SiHoltye]

Hello,

Thinking about this Ordinary Bitter for next, utilizing a touch of Brown hopefully to achieve a smidge of biscuit-iness, with hopefully a smidge of orange-iness from the First Gold.

Ingredients
25L, 90min mash @ 67°C, 90 min boil
Amount Item Type % or IBU
3.90 kg Maris Otter (5.9 EBC) Grain 92.86 %
0.25 kg Caramel/Crystal Malt - 40L (78.8 EBC) Grain 5.95 %
0.05 kg Brown Malt (150.0 EBC) Grain 1.19 %
30.00 gm First Gold [7.50 %] (90 min) Hops 22.7 IBU
10.00 gm First Gold [7.50 %] (30 min) Hops 5.4 IBU
15.00 gm First Gold [7.50 %] (0 min) (Aroma Hop-Steep) Hops -
1 Pkgs English Ale (White Labs #WLP002) Yeast-Ale

Beer Profile
Est Original Gravity: 1.040 SG
Est Final Gravity: 1.012 SG
Bitterness: 28.2 IBU
Est Color: 12.8 EBC

Total water I need to prepare is 35.8L, to which I planned to add 9.1g Gypsum, and 11.57g of Calcium Chloride flakes using GW's calc to hit 'Bitter' profile. Are specific minerals added at different stages, or do I 2 thirds/1 thirds MT/Boiler. or is something else appropriate? Thanks for any help.