While working on this PR https://github.com/bitcoin/bitcoin/pull/18570 I ran into a bit confusing situation where in one function a **CWallet reference** was expected while two others dealt with **CWallet pointers**. My initial reaction was: `let's harmonize them by making them references`. However, not being part of the PR itself I did't change anything and completed the PR first.

Now, after having analyzed the `rpcwallet.cpp` code I came to the conclusion that:

* converting them all into references is not the solution as they're originally **shared_ptr**s
* but also: there is no (visible) reason why every RPC function should begin like this:

```cpp
std::shared_ptr<CWallet> const pwallet = GetWalletForJSONRPCRequest(request);
const CWallet* const pwallet = wallet.get();
```

This clearly defeats the purpose of shared pointers for no obvious reason. *Maybe I am missing something?*

In my (unpublished) [code changes](https://github.com/brakmic/bitcoin/commit/0b3ee615491edf6f542631bf6ae6f72eac406550) all raw pointers got replaced with **shared_ptr**s but kept their original names (that is, *pwallet*). In the end, they're pointers too, so the most of the original code remained untouched.

However, some of the helper functions couldn't be changed because external code is accessing them and I didn't want to make this task "virulent". So I introduced new ("Ref") variants that expect **shared_ptr** parameters, namely: 

```cpp
void EnsureWalletRefIsUnlocked(const std::shared_ptr<CWallet>);
bool EnsureWalletRefIsAvailable(const std::shared_ptr<CWallet>, bool avoidException);
```

I have tested the code, with python and boost-tests, and could not find any errors. 
But before opening a PR I would like to open a discussion about this. 

Is there any reason to keep on working with raw pointers when every function call actually begins with *shared_ptr*s?

Regards,
throw JSONRPCError(RPC_WALLET_ERROR, "importdescriptors is not available for non-descriptor wallets");
    }
    RPCTypeCheck(main_request.params, {UniValue::VARR, UniValue::VOBJ});
    WalletRescanReserver reserver(*pwallet);
    if (!reserver.reserve()) {
        throw JSONRPCError(RPC_WALLET_ERROR, "Wallet is currently rescanning. Abort existing rescan or wait.");
    }
    const UniValue& requests = main_request.params[0];
    const int64_t minimum_timestamp = 1;
    int64_t now = 0;
    int64_t lowest_timestamp = 0;
    bool rescan = false;
    UniValue response(UniValue::VARR);
    {
        LOCK(pwallet->cs_wallet);
        EnsureWalletIsUnlocked(pwallet);
        CHECK_NONFATAL(pwallet->chain().findBlock(pwallet->GetLastBlockHash(), FoundBlock().time(lowest_timestamp).mtpTime(now)));
        
        for (const UniValue& request : requests.getValues()) {
            
            const int64_t timestamp = std::max(GetImportTimestamp(request, now), minimum_timestamp);
            const UniValue result = ProcessDescriptorImport(pwallet, request, timestamp);
            response.push_back(result);
            if (lowest_timestamp > timestamp ) {
                lowest_timestamp = timestamp;
            }
            
            if (!rescan && result["success"].get_bool()) {
                rescan = true;
            }