Agreed, I think ag-waste shows the most promise, unfortunately there are not many suppliers - the authors mention that bio-based construction products have the potential to sequester even more CO2 than wood:
In addition to timber, other traditional bio-based materials, for example, bamboo, straw, hemp, and emerging bio-based materials with high carbon content (~90% instead of ~50% for wood) need to be explored. Optimal mixtures of bio-based construction materials will likely depend on the local climate and the natural resources available.
CarbonCure sequesters ~500 g CO2 per m3… Solidia has some promise but is only for precast AFAIK. I like Blue Planet, but am not sure if they’ve had much market success, do you know if they have supply capacity to B.C., or even in SFO?