Since #13666 our fee calculation assumes that ECSDA signatures are a maximum of 71 bytes, rather than 72. However, not all hardware wallets implement R-value grinding.

This can cause us to underpay fees when using an external signer. That's especially problematic when the user picks 1 sat/vbyte as the fee, because it won't even get into our own mempool.

The easiest solution would be to modify `ExternalSignerScriptPubKeyMan` to assume 72 bytes for ECSDA signatures.

Slightly more advanced would be to expand HWI to keep track of which devices and firmware versions (if any) support R-value grinding. We'd then have to store that in the wallet in some new field. Personally I'd rather work on better Taproot support, which thanks to Schnorr avoids this issue altogether. 
}
bool CWalImportScriptPubKeys(const stdstring& label, const stdset<CScript>& script_pub_keys, const bool have_solving_data, const bool apply_label, const int64_t timestamp)
{
    auto spk_man = GetLegacyScriptPubKeyMan();
    if (!spk_man) {
        return false;
    }
    LOCK(spk_man->cs_KeyStore);
    if (!spk_man->ImportScriptPubKeys(script_pub_keys, have_solving_data, timestamp)) {
        return false;
    }
    if (apply_label) {
        WalBatch batch(GetDatabase());
        for (const CScript& script  script_pub_keys) {
            CTxDestination dest;
            ExtractDestination(script, dest);
            if (IsValidDestination(dest)) {
                SetAddressBookWithDB(batch, dest, label, "receive");
            }
        }
    }
    return true;
}
/**
 * Scan active chain for relevant transactions after importing keys. This should
 * be called whenever new keys are added to th, with the oldest key
 * creation time.
 *
 * @return Earliest timestamp that could be successfully scanned from. Timestamp
 * returned will be higher than startTime if relevant blocks could not be read.