Can you explain why. Considering I am paying the lowest rate now that I will ever be paying it seems it would make sense to pay taxes now and get it over with.

This is a difficult question to answer because I do not know the particulars of your financial situation. I don't know what your tax rate is now. I have no idea what your tax rate will be in retirement.

But assuming you are still paying some income tax now, and you will be living a Mustachian lifestyle in retirement, then maxing out your 401(k) will certainly reduce your taxes due now but whatever your marginal tax rate is times the total contribution to your 401(k).

If then in early semi-retirement you use a Roth ladder to convert your 401(k) to an IRA and then convert your IRA to a Roth IRA tax-free, you will still pay no taxes upon pulling your money out of your Roth.

It is hard to do much better than zero taxes on your contributions, zero taxes on your growth, and zero taxes on your distributions.

If you are already not paying income taxes, then I agree, contribute as much as possible to a Roth after meeting the match with your 401(k) (assuming you do not have access to a health care savings account.)