### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current behaviour

See inline discussion at https://github.com/bitcoin/bitcoin/pull/26467#discussion_r1269177446

@whitslack:

> Consider the case where I am paying someone on chain under the stipulation that _they_ will eat the mining fee. (Thus, I specify _their_ address in `subtractfeefrom` when I'm constructing my transaction.) Later, they tell me that they can't wait for confirmation any longer and need an urgent fee bump. If I naïvely specify their output as the `reduce_output`, I may end up paying them _**much more**_ than I intended to if I only have large UTxOs in my wallet.


### Expected behaviour

Not sure.

Improving the docs is one option, but this behaviour seem quite counter intuitive.

My own suggestion:

> Should we disable the adding of new inputs when `reduce_output` is set? If someone really intends to do that, they should probably use `outputs`.

### Steps to reproduce

Haven't tried.

### Relevant log output

_No response_

### How did you obtain Bitcoin Core

Compiled from source

### What version of Bitcoin Core are you using?

Master after #26467

### Operating system and version

Any

### Machine specifications

_No response_
* @param[out] old_fee The fee the original transaction pays
 * @param[out] new_fee the fee that the bump transaction pays
 * @param[out] mtx The bump transaction itself
 * @param[in] require_mine Whether the original transaction must consist of inputs that can be spent by the wallet
 * @param[in] outputs Vector of new outputs to replace the bumped transaction's outputs
 * @param[in] reduce_output The position of the change output to deduct the fee from in the transaction being bumped
 */
Result CreateRateBumpTransaction(CWallet& wallet,
    const uint256& txid,
    const CCoinControl& coin_control,
    std::vector<bilingual_str>& errors,
    CAmount& old_fee,
    CAmount& new_fee,
    CMutableTransaction& mtx,
    bool require_mine,
    const std::vector<CTxOut>& outputs,
    std::optional<uint32_t> reduce_output = std::nullopt);
bool SignTransaction(CWallet& wallet, CMutableTransaction& mtx);
Result CommitTransaction(CWallet& wallet,
    const uint256& txid,
    CMutableTransaction&& mtx,
    std::vector<bilingual_str>& errors,
    uint256& bumped_txid);
struct SignatureWeights
{
private:
    int m_sigs_count{0};
    int64_t m_sigs_weight{0};
public:
    void AddSigWeight(const size_t weight, const SigVersion sigversion)