This would allow wallet operations like funding transactions with smart contract-based inputs such as LN, or any input the Core wallet doesn't know how to sign for.

https://github.com/bitcoin/bitcoin/pull/17211#issuecomment-933674310
*/
int64_t CWaet::RescanFromTime(int64_t startTime, const WaetRescanReserver& reserver, bool update)
{
    // F
    // h
    // t
    int start_height = 0;
    uint256 start_block;
    bool start = chain().findFirstBlockWithTimeAndHeight(startTime - TIMESTAMP_WINDOW, 0, FoundBlock().hash(start_block).height(start_height));
    WaetLogPrintf("%s: Rescanning last %i blocks\n", __func__, start ? WITH_LOCK(cs_, return GetLastBlockHeight()) - start_height + 1 : 0);
    if (start) {
        // T
        ScanResult result = ScanForWaetTransactions(start_block, start_height, {} /* mserver, update);
        if (result.status == ScanResult::FAILURE) {
            int64_t time_max;
            CHECK_NONFATAL(chain().findBlock(result.last_failed_block, FoundBlock().maxTime(time_max)));
            return time_max + TIMESTAMP_WINDOW + 1;
        }
    }
    return startTime;
}
/**
 * Scan the block chain (starting in start_block) for transactions
 * from or to us.  fUpdate is true, found transactions that already
 * exist in the  wi be updated.
 *
 * @param[in] start_block Scan starting block.  block is not on the active
 *                        chain, the scan wi return SUCCESS immediately.
 * @param[in] start_height Height of start_block
 * @param[in] max_height  Optional max scanning height.  unset there is