What to do with some extra money?

I’m 38, make 165k salary. married file jointly with a stay at home wife, 2 kids.

-Paid off house $ car (share, I WFH)

-370k in traditional 401k

-50k in Roth IRA / maxing

-50k in spousal Roth IRA / maxing

-50k in 529

-20k in HSA / maxing

-30k brokerage / $500 a month in

-50k cash

I am maxing out both of our Roths and our HSA. I stopped contributing to my traditional 401k as we have no match and I want some more money for the in between years.

I just got a side gig consulting that I expect to make 20-25k a year in. it is 1099c I’ve never done 1099 and don’t have much if anything to write off so I’m wondering what my best option here is.

I know technically I should probably max the 401k to save 4-6k a year on taxes but I really like the idea of bolstering the accounts I can touch in those in between years, too. Wondering if I should do a Solo Roth 401k and pump in the money from the 1099 gig for a while and then convert it to my Roth IRA after (assume I can do that) or just find any write offs I can and lower that 1099 money as much as I can and just pump it into a brokerage? Any suggestions would be helpful keeping in mind my goals of flexibility now-retirement.

im not really looking to retire early per se I just want independence as soon as I can get it as I don’t know if the gettin will be this good for me forever 🙂