Yes, it is very reasonable. But that'd also involve using your legal team's help in corroborating the language around this. If for some reason, in a certain year, the company can't facilitate this process, then the company shouldn't be in a tough spot.
At Carta, all employees (given the stage of the company) are offered RSUs, and buybacks happen every now and then. Here's the language that was used in our offer letters -
Carta Liquidity Events
Carta provides the opportunity for employees to sell shares of stock in a liquidity event on a periodic basis. There are a number of factors that go into the timing of liquidity events including investor demand, overall supply, general economic and market conditions, and other company events (such as funding rounds). Therefore, it is hard to predict an exact cadence of when these occur. However, Carta is committed to offering liquidity events on an ongoing basis.
Eligibility to Participate in a Carta Liquidity Event
An employee that has eligible shares can choose to submit orders in these liquidity events. Eligible shares are shares that have been settled AND held for at least 6 months (“Mature Shares”). Carta has held many liquidity events including CartaX transactions and tender offers over the past several years. Historically, current employees have been eligible to submit orders up to 20% of their total vested shares. Former employees have been able to submit orders up to 10% of their total vested shares.