Allow wallets to specify limited CoinType support?

[JeremyParish69]

Should we allow Wallets to specify whether they will only generate CoinType 60 keys, as is the case for MetaMask? Or is this not helpful?
I figure most wallets will be able to suggest for any CoinType, so I'm not sure it's handy for most cases, but there might be more use in specifying only when wallets support a limited number of CoinTypes: So if it's missing, assume all CoinTypes are supported, and if it's listed, then assume only the specified CoinTypes are supported.

e.g., for MetaMask:

{
  ...,
  coinTypes: [
    60
  ],
  ...
}

but for Keplr, there would be no such property, because it supports any CoinType under BIP44