I agree with 5m0k3e it takes far too long to smelt while out mining, either do it while on downtime or just mail those ores off.
I can see a use for it if say Ghost Iron Ore is worth crap on the AH and the bars are worth making anyway as this would make the bot look more "real" to stop and suddenly smelt all the ore into bars.
However at some point you will still need to mail off the Ghost Iron Bars and you also have to leave bag space for thermal anvils, all things being equal I think what you want is quite inefficient and I think it would be a more difficult plugin to code for.