OAuth 2 for Bitcoin Wallets: best practices

[dragons_are_secure]

 IETF recently came out with recommendations for best practices for Native Apps using OAuth 2.  It got me wondering whether the protocols for those using Native Apps for Bitcoin Wallets should be improved.

 Here's the IETF:
  https://www.rfc-editor.org/rfc/rfc8252.txt

The short summary is that they recommend adopting a PKCE like exchange.  My understanding is that this is not currently in most Wallet API flows:
  (e.g. : https://developers.coinbase.com/docs/wallet/coinbase-connect)