Commonly set up? Depends on what you mean by "like this" - for this exact purpose, probably not at all. Enforceable? Absolutely. The entire point of a trust is

Commonly set up? Depends on what you mean by "like this" - for this exact purpose, probably not at all. Enforceable? Absolutely. The entire point of a trust is to give out flows of cash to beneficiaries while restricting certain rights you may not want those beneficiaries to have. Usually this is more along the lines of "can't use the assets to pay down debts" than ensuring that the wealth generated from founding a start-up gets distributed fairly.