Radiologist here. Also have an s-corp in CA. Unfortunately for me, I am part of a general partnership and therefore cannot do a solo CBP.
You are in the perfect place for tax savings. solo practice s-corp high income earner.
Pay yourself a reasonable salary (200k is fine. SS taxes max out around 150k so you are really only paying a bit more medicare tax. you pay income tax on distributions either way). Take the rest as a distribution. Set up a CBP with schwab or pay a bit more an have some place like Emparion to set it up (~1750-2000 a year, fully deductible). Max that out for your age (mid 30s is between 80-90k to well over 200k decades later). Then max out employee solo 401k contribution of 22,500. Then max out your employer 401k contribution (limited to 6% NOT 25% of income when used with a CBP; i.e. 200k income you can put 12k only). To make up the difference you can do a mega backdoor roth. Consider using an HSA to further reduce taxable income. Deduct office expenses, home office deduction, CME costs, mortgage interest deduction, charitable donations, etc.
After 5-7 years of the CBP. Close it and then transfer funds to a 401k. Then start a new one.
Then take advantage of the PTE elective tax to be able to bypass the SALT deduction cap put in place in 2017 by Trump. This alone is a huge advantage over W2 income in CA.
If you can get your taxable income below the limits for the Qualified Business Income deduction then you get another 20% deduction. That is why the CBP is great because it lowers your income below the threshold.
Emparion has a good example of the combo solo 401k and CBP
here. Go down to example #1 "The Combo"