I don't have time to get into any detail but look into Bacillus Subtilis, it's a Naturally occurring antifungal bacteria found in soils.
It's a rhizobacteria which means it will inoculate the root zone
Inoculating can help the plants fight off pests and diseases and they are also one of the best bacteria for improving phosphorus uptake for cannabis and that's a plus because phosphorus is considered a macronutrient and one of the most difficult to uptake. Plus Bacillus Subtilis can survive harsh conditions, so they will survive in the soil in some of the most extreme regions of the Country.
BT quickly degrades with the UV exposure from the Sun and works best when applied in the evening.
I've never heard of inoculation of the plants tissues with BT due to it being a bacterium derivative from the soil that works best when caterpillars are still in the lava stages.
Also if relied on to heavily the caterpillars can build a resistance to BT