### 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_
CAmount new_outputs_value = 0;
    const auto& txouts = outputs.empty() ? wtx.tx->vout : outputs;
    for (size_t i = 0; i < txouts.size(); ++i) {
        const CTxOut& output = txouts.at(i);
        CTxDestination dest;
        ExtractDestination(output.scriptPubKey, dest);
        if (reduce_output.has_value() ?  reduce_output.value() == i : OutputIsChange(wallet, output)) {
            new_coin_control.destChange = dest;
        } else {
            CRecipient recipient = {dest, output.nValue, false};
            recipients.push_back(recipient);
        }
        new_outputs_value += output.nValue;
    }
    
    if (recipients.empty()) {
        
        if (std::get_if<CNoDestination>(&new_coin_control.destChange)) {
            errors.emplace_back(Untranslated("Unable to create transaction. Transaction must have at least one recipient"));
            return Result::INVALID_PARAMETER;
        }
        
        
        recipients.emplace_back(CRecipient{new_coin_control.destChange, new_outputs_value, true});
        new_coin_control.destChange = CNoDestination();
    }
    if (coin_control.m_feerate) {