If you don't burn taxable assets, there is no worry with dividends and capital gains. You will NOT get a 1099-DIV or 1099-B because of capital gains or dividends in an IRA. You are in control (until age 70.5) of how much you withdraw from it. You will get a 1099-R for the withdrawn amount in a TIRA, and that is ordinary income. If you want $58K, take out $58K. It doesn't matter how the value inside the account grows.
If you burn taxable assets along the way, that is where selling stocks that generate capital gains -- or holding dividend stocks -- will hit you, and where you would have a 1099-B, and where you'd have dividend income to declare on a 1099-DIV. Not from IRA withdrawals.
That said, unless you are taking SEPP (72t) or are over 70.5 years old, you can control how much you withdraw year to year. So if you wind up taking $5K in taxable dividends and cap gains, you can withdraw $53K instead of $58K in the IRA and your MAGI for ACA purposes remains the same.