Nice work!
I use 7% returns (could do 7.2% to simplify rule of 72) in my calculations. Consider the breakdown of your retirement accounts, how much is tax deferred vs. tax free). I use a 3% rule for an early retirement and because I'm conservative.
You can access your retirement accounts via the 72T at any point, penalty free, you can access your Roth contributions penalty free at any point. There is also the rule of 55 that may or may not apply, employer dependent, that allows you to withdraw from your retirement accounts when you retire or are terminated in the year you turn 55 or later.
I'd take a look at your balance in your retirement accounts and if you are considering not doing a tax deferred investment in your 457/401k I would do a Roth contribution in those accounts rather than going into taxable as it would be tax free gains.
That said, I think it is prudent to invest in taxable investments also, to be able to better manage taxes later on. I'd also consider what you might want to spend in retirement vs. now. You don't want to blow more now and get used to it and not be able to support that in retirement.