Also, don't forget, that the work itself can be about 'preparing the ground' for your non-charitable interests (which are probably held in trust, ie not held personally). Eg if you involve yourself in child education (perhaps making it worse) this is not an issue if it makes it more like that your classroom software is adopted. Or, if you are heavily invested in pharmaceuticals, singing the praises of vaccines, is just a tax savvy way of increasing the market that you will benefit from.