Downpayment now, or invest and recast?

We are kind of extreme savers, but poor investors. Collectively save about 12% monthly in our retirements, but have socked away a lot more for a home, continuing education, rainy day, etc. that most here would scold us for not investing.

We are looking into building a home, using a construction loan with an upfront closing. We have about $225,000 earmarked to put down. My question is: would we be wise to put down the minimum up front, stick the remainder in a 5% money market fund (this money needs to be almost assured as safe, so something higher yield with risk of loss is not an option) and let it ride there until the home is done. Then lump-sum pay toward the principal and pay for a recast to put the payments back where we initially wanted them?

I know the best financial approach is always to put down the minimum and invest, but we are 100% focused on achieving the smallest possible payment.

If we were to simply purchase a home in the market, is it likewise good advice to choose a downpayment that secures the best rate, then immediately pay in on the principal and recast to set the payments bs k where you wanted them? Some of our local lenders really penalize us for the large downpayment, so if I can cheat that system, I’m all about it.