BIP118 (SIGHASH_NOINPUT) vs. ANYPREVOUT
I perceive the motivation for SIGHASH_NOINPUT – it could assist with offchain fee channels. It was proposed already within the Lightning paper however Eltoo will successfully work simply with one thing like that. However what precisely is the ANYPREVOUT BIP about? It looks as if some extension for use with taproot scripts. However I do not appear to get why you want a particular public key sort and chaperone signatures. Can anybody clarify this half in plain english please?