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.
{
    AssertLockHeld(cs_);
    std::map<uint256, CWalletTx>::const_iterator mi = mapWallet.find(txin.prevout.hash);
    if (mi != mapWallet.end())
    {
        const CWalletTx& prev = (*mi).second;
        if (txin.prevout.n < prev.tx->vout.size())
            return IsMine(prev.tx->vout[txin.prevout.n]);
    }
    return ISMINE_NO;
}
CAmount CWallet::GetDebit(const CTxIn &txin, const isminefilter& filter) const
{
    {
        LOCK(cs_);
        std::map<uint256, CWalletTx>::const_iterator mi = mapWallet.find(txin.prevout.hash);
        if (mi != mapWallet.end())
        {
            const CWalletTx& prev = (*mi).second;
            if (txin.prevout.n < prev.tx->vout.size())
                if (IsMine(prev.tx->vout[txin.prevout.n]) & filter)
                    return prev.tx->vout[txin.prevout.n].nValue;
        }
    }
    return 0;
}
isminetype CWallet::IsMine(const CTxOut& txout) const