This is a private agreement, as long as it is not mandatory, it should be no problem, but I suggest that you must write it into the contract. An oral agreement is not legally binding. For example, your 20 thousand yuan counts as one. As for whether it is worth painting, it depends on your idea. After all, if you suddenly quit, it is not impossible for others to recruit another 20 thousand yuan as a deposit. The key is to write your requirements into the contract after negotiation, and then they can sue according to the contract if they want to breach the contract.