Straight biochar (wash the ash off of it and wash it well) will not change soil pH. It will begin to act like a pH buffer and stabilize pH shifts but I wouldn't do anything too drastic to test that like dumping a bunch of wood ash on the soil.
Discussion
Yeah definitely going to err on the conservative side,
Going to test an idea I had for it actually rather than applying directly to the growing areas - I'll test the ph periodically hopefully as well.