According to Fidelity:
You can contribute up to $69k combined from Employee and Employer if your employer allows it. Catch up is $7500. Unlike Roth IRAs, Roth 401(k)s don't have any income limits. Regardless of how much you earn, you can contribute to a Roth 401(k) if your employer offers one. Since I'm both the employee and employer, I can allow such contributions. The problem is TurboTax doesn't have a way to take advantage of this without some convoluted workaround per your suggestion which will negate my ability to e-file. See URL below.
https://www.fidelity.com/learning-center/smart-money/roth-401k-contribution-limits
