I was playing around with a probably-too-cute script for LN channel smart contract, and was looking for something to decide for me if miniscript can infer the structure of the script.

f.e.

```
decodescript 82012088a914ffffffffffffffffffffffffffffffffffffffff8820ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffad51b2

{
  "asm": "OP_SIZE 32 OP_EQUALVERIFY OP_HASH160 ffffffffffffffffffffffffffffffffffffffff OP_EQUALVERIFY ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff OP_CHECKSIGVERIFY 1 OP_CHECKSEQUENCEVERIFY",
  "desc": "raw(82012088a914ffffffffffffffffffffffffffffffffffffffff8820ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffad51b2)#5guaahuv",
  "type": "nonstandard",
  "p2sh": "33YyjgxsJYwSi8Wbp7TaCSFAuJBoUfYWDQ",
  "segwit": {
    "asm": "0 99f5d0b69f9828fea9363198cf812e95d7fc5e94c7881092b8e3f43984c1bd5c",
    "desc": "addr(bc1qn86apd5lnq50a2fkxxvvlqfwjhtlch55c7yppy4cu06rnpxph4wqrar3md)#wtlf0gwk",
    "hex": "002099f5d0b69f9828fea9363198cf812e95d7fc5e94c7881092b8e3f43984c1bd5c",
    "address": "bc1qn86apd5lnq50a2fkxxvvlqfwjhtlch55c7yppy4cu06rnpxph4wqrar3md",
    "type": "witness_v0_scripthash",
    "p2sh-segwit": "3MRJN2wTnD2BVm31HLcBwueAYpbbximrtk"
  }
}
```

Since it's evaluated at "top level for `desc` it cannot get any meaningful structure from it. Perhaps in `segwit` it could try infering the miniscript in the segwit context


"\nConvert the transaction to a PSBT\n"
                            + HelpExampleCli("converttopsbt", "\"rawtransaction\"")
                },
        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
    
    CMutableTransaction tx;
    bool permitsigdata = request.params[1].isNull() ? false : request.params[1].get_bool();
    bool witness_specified = !request.params[2].isNull();
    bool iswitness = witness_specified ? request.params[2].get_bool() : false;
    const bool try_witness = witness_specified ? iswitness : true;
    const bool try_no_witness = witness_specified ? !iswitness : true;
    if (!DecodeHexTx(tx, request.params[0].get_str(), try_no_witness, try_witness)) {
        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
    }
    
    for (CTxIn& input : tx.vin) {
        if ((!input.scriptSig.empty() || !input.scriptWitness.IsNull()) && !permitsigdata) {
            throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Inputs must not have scriptSigs and scriptWitnesses");
        }
        input.scriptSig.clear();
        input.scriptWitness.SetNull();
    }
    
    PartiallySignedTransaction psbtx;
    psbtx.tx = tx;
    for (unsigned int i = 0; i < tx.vin.size(); ++i) {
        psbtx.inputs.push_back(PSBTInput());
    }
    for (unsigned int i = 0; i < tx.vout.size(); ++i) {