Before adding in all these alkaline sources that defeat the purpose of acidification.
For now set them aside for now till you get the pH under control. Then you can try adding one in at a time to see if the pH will hold.
For now continue with the HHB and add more calcium from Calcium citrate, an acidified form of Calcium.
If you get the Frontier Naturals 1b. I can recommend a measure.
Yes, you can feed cooked white rice, yet the oats are a better choice.
If you can't get the oats for a few days then add in boiled cooled white rice.
Old fashioned rolled oats quick cook, not instant, from Bob's red mill. Available on Amazon.com
Oregon Mushroom carries frozen huckleberries.
Mushroom powder: Chanterelle, or Yellowfoot from "Oregon Mushroom" online.
They list a higher portion high price; look for the smaller amount they also carry on their website.
Soak nuts in yogurt overnight, then dry them on low heat in the oven. Feed no more than 1/2 Tsp. of chopped nuts daily.
This not only lowers pH, but lowers oxalates and phytates making calcium and phosphorus more bioavailable.
No cinnamon, Pycnogenol from either Healthy Origins extract dried, or Organika liquid both available on Amazon.com
https://www.amazon.com/Organika-PYCN...iquid+organika
Yet MTS is alkaline; I would try the liquid elixir from Oregon Wild harvest.
https://www.amazon.com/Oregons-Wild-.../dp/B00J9MKEUG