I think in general, your situation is pretty good, and maxing tax advantaged accounts is a good thing.
Having only $20K in taxable is light by my personal preferences, but I acknowledge that it's a personal preference and not some true piece of wisdom.
The missing piece of the puzzle is whether you have any life plans that will require a big chunk of capital in the near future. For example, are you planning on buying a house, moving, or buying a car with all cash in the next few years? If so, get those funds easily accessible in a taxable account first. These big things commonly happen around the time kids come along.
With a kid coming, I'd also bulk that taxable amount up to $50K-$100K just to add some life flexibility in case life happens. You can go back to maxing tax advantaged accounts after that.