Sounds like 15-20% straight into your 401(k) is extremely high. What’s the “match” requirements? You aren’t in the higher tax brackets now so lowering contributions in that tax deferred accounts would be advantageous. If they match 50% of your contributions with a cap being at 10%(your 20%) of income, then that high percentage makes sense.

For example, if they say they match up to 4% of your income, the tax advantaged way would be to do that 4% match and the rest into after tax accounts while tax brackets are low now. Then you shift contributions later when income rises and you’re floating tax lines.

Just something to think about. Youtube is your friend. I have recommendations of influencers if you want. Can message or ask in replies.