Solo 401k & 199A Deductions

My spouse will be starting as a 1099 physician in the fall and we're working on setting up an S Corp, so I have two questions:

Solo 401k -- It seems like the minimum salary to be taken is $150k in order to max this out, correct? I know about the "reasonable salary" consideration, but is there anything else to think about here, except for the usual "investment stuff"?

199A Deductions -- It's unlikely we will qualify for this since I am starting a new job W-2 job in 2 weeks making ~$115k, so we're blowing past that $415k limit since my spouse's expected salary is $450-500k, but is there any way to structure her business (e.g. something about increasing or decreasing salary) to get this deduction?

Thanks for any help. We're currently in boring old W-2 jobs (well, I just finished up a two-year postdoc), so all of this is new.