I think one important decision to make is For nq and es futures we have to do autoconvert, the symbols to be used are SPY and QQQ. For any other instrument, we have to use it directly in schawab to see if we get the option chain, if not we have to map to a closet ETF option chain stored in a internal table/array. this is with no autoconvert flag in the NT indicator parameters. Giving price multiplier and offset without autoconvert flag will be misleading. all thee or none imo.