Set List Price to 0 – Does anyone do this?

On this page (https://sellercentral.amazon.com/help/hub/reference/G202170370?locale=en-US), Amazon suggests this:

If you do not have a ready-to-provide List Price, a possible value could be the first price at which you offered or will offer the product. You can also provide a value of 0 to indicate you do not have a List Price. If Amazon cannot verify your List Price, we might not use it.

Does anybody do this? Is it good practice?

I sell unique products, so any MSRP doesn’t apply to me.

Is it best to leave List Price blank? Set it to 0? Set it to the same as my Price? Or do something else?

Amazon is always bugging me to set a List Price. I’m thinking they want me to set it to something rather than leaving it blank as I have it now.