Spread operator in flow - works better with $Exact<T> or with exact types

ExactSpread.js

// @flow
type HaveHeyType = {
  hey: number,
};

type HaveBeeType = {
  bee: string,
};

type SpreadIsUselessType = {
  ...HaveHeyType,
  ...HaveBeeType,
};

type ExactSpreadWorksGreatType = {
  ...$Exact<HaveHeyType>,
  ...$Exact<HaveBeeType>,
};

const c: SpreadIsUselessType = {
  hey: 1,
  bee: 'honey gatherer',
};

// No fail, even though it is missing 'bee'.
const cBad1: SpreadIsUselessType = {
  hey: 1,
};

// No fail, even though it is missing 'hey'.
const cBad2: SpreadIsUselessType = {
  bee: 'honey gatherer',
};

// No fail, even though it has values with the wrong types for 'hey' and 'bee'!
const cBad3: SpreadIsUselessType = {
  hey: 'bad',
  bee: 999,
};

const d: ExactSpreadWorksGreatType = {
  hey: 3,
  bee: 'technically bees gather *nectar* and make honey. they do not gather honey directly',
}

// Uncomment to get an error because 'bee' is missing.
/*
const dBad1: ExactSpreadWorksGreatType = {
  hey: 3,
};
*/

// Uncomment to get an error because 'hey' is missing.
/*
const dBad2: ExactSpreadWorksGreatType = {
  bee: 'bumble',
};
*/

// Uncomment to get an error because 'hey' and 'bee' have values with wrong types
/*
const dBad3: ExactSpreadWorksGreatType = {
  hey: 'bad',
  bee: 999,
};
*/

type ExactlySeaType = {|
  sea: Object,
|};

type ExactlyOtterType = {|
  otter: string,
|};

const aSea: ExactlySeaType = {sea: {}};
const anOtter = {otter: 'mitch'};

type SeaOtterType = {
  ...ExactlySeaType,
  ...ExactlyOtterType,
};

const aBoth: SeaOtterType = {
  sea: {},
  otter: 'wet',
};

// Uncomment to get an error because 'sea' and 'otter' have values with wrong types
/*
const badBoth: SeaOtterType = {
  sea: 'wrong',
  otter: {},
};
*/