I set up runners, but i left the default of 10 threshold. If i change that, can i just delete runner.state, change the mainRunner.py threshold from 10 to whatever i want, then restart mainRunner and that will just adjust the threshold for the reserve guys? I wouldnt want them to start after a disaster and go back to cash in with only 10 coins. That seems like a time to stock up.... "I don't want it to create a whole new set of runners, i just want it to change the threshold on the existing reserve guys.
Note that the 10-HUC treshold does not apply to the "first" run - on the first run, hunters collect until no more coins are visible in range around their centre. They only go back when they have both 10 HUC and no more coins are immediately lying around. Maybe this resolves your question already. Apart from that, I have to admit that I think it is not easily possible right now to change the configuration of the runner guys - since they are currently in registration, you would lose the name_new coins if you delete the runner.state file.
One solution is to remember the name/rand/txid values (found in the runner debug output) and then restart the process. It will create new reserve players (costs you HUC again), but with your rand/txid values, you can always manually activate the others and make use of them in normal play (or for the gatherers, for instance).