OK, now that's funny.

We cannot have PRAP contributions based on income greater than 280k, or 285k for 2020, due to 401(a)(17) limit.

If you make 385k, you are 100k above the limit and your 16% B&C will spill to the RHA. ($16,000 to RHA)

Nothing can be done about that.

415(c) limit is another issue and the amount that spills can somewhat be controlled by the timing and amount of your contributions.

Want to maximize spillage to RHA? Put in as much as you can as early in the year as possible.

Want to minimize it? Put in less. In this example you would put in 17,900 to combine with the 45.6k to equal 63.5k.

you can run some howgozits at online RHA Calculator at

RHACalculator.com

It was just updated for 2020 numbers and based on your inputs will show how much will spill and and let you change contributions easily to see how it flows.

Unofficial, but works well and gives you breakdowns on the type of spill and potential balance at retirement.