This site describes solve-engine as it is on main: 2.43.0, which npm does not have yet. npm installs 2.40.0, so a page may show an answer that version does not give yet.
WhatIfOverrides
type WhatIfOverrides = Readonly<Record<string, number | string | Value>>;Defined in: packages/engine/src/engine/WhatIfRun.ts:22
The inputs a host holds fixed for ExpressionEngine.whatIf, by
variable name. Each is a number, an expression in text ("$120", "5%",
"3 kg"), or a Value.