Would it be completely unreasonable to allow `fundrawtransaction` to use unsafe outputs?

I understand this means the resulting transaction may be invalidated whenever the unsafe output I'm relying one disappears (e.g. because the transaction that produced it was RBF-ed) but in my case that's ok, I'll react to that and re-publish the tree of child transactions accordingly.

But let me know if you think that's too much of a footgun for users, in that case I'll architect my solution differently.
{
    if (p == nullptr)
        return 0;
     Avoid caching ismine for NO or ALL cases (could remove this check and simplify in the future).
    bool allow_cache = (filter & ISMINE_ALL) && (filter & ISMINE_ALL) != ISMINE_ALL;
     Must wait until coinbase is safely deep enough in the chain before valuing it
    if (IsImmatureCoinBase())
        return 0;
    if (fUseCache && allow_cache && m_amounts[AVAILABLE_CREDIT].m_cached[filter]) {
        return m_amounts[AVAILABLE_CREDIT].m_value[filter];
    }
    bool allow_used_addresses = (filter & ISMINE_USED) || !p->IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE);
    CAmount nCredit = 0;
    uint256 hashTx = GetHash();
    for (unsigned int i = 0; i < tx->vout.size(); i++)
    {
        if (!p->IsSpent(hashTx, i) && (allow_used_addresses || !p->IsSpentKey(hashTx, i))) {
            const CTxOut &txout = tx->vout[i];
            nCredit += p->GetCredit(txout, filter);
            if (!MoneyRange(nCredit))
                throw std::runtime_error(std::string(__func__) + " : value out of range");
        }
    }
    if (allow_cache) {
        m_amounts[AVAILABLE_CREDIT].Set(filter, nCredit);
        m_is_cache_empty = false;
    }
    return nCredit;
}
CAmount CWalletTx::GetImmatureWatchOnlyCredit(const bool fUseCache) const