The point of vesting is to exchange shares for value as the value in the form of work is provided over a period of time.
If some of the value you provided was in the form of cash then the corresponding shares should be yours the moment you transferred the money.
Please note that I’ve not actually implemented this myself. In my company we just split all the shares evenly on day one with no vesting schedule.
It’s been kind of interesting because no one has any real authority over the others and the few major disagreements we’ve had were solved by whoever was quickest in performing a fait accompli. This has resulted in occasional shouting and aggressive behaviour.
