If you reinvest it into the stock, you've had to pay taxes on the dividend amount, so you've lost vs a buyback.
If you want to spend money and your stocks don't issue dividends, you just have to sell some of your shares. Selling $X of shares will almost always generate less taxable income than receiving $X of dividends as some of it will be a return of capital; so again, if you take $X out of the holdings, you've lost with a dividend vs a buyback and you sold $X.
Any time you want that to happen for you, simply press the sell button for some percentage.
Why would you want the company to decide the timing and the percentage for you?