Have the reactor controller have a GUI to allow you to do one (or more) of the following
- Check box - Switch from omni-directional redstone current signal to FACE Specific redstone current signal.
- This would allow you to use the Controller as a trigger for an external, user created circuit
- Optionally - A Plus pattern (with a long side *extra box*) of check boxes. You then choose which faces emit a redstone signal. (6 check boxes total for the 6 sides)
- Same as above, except you can also place this controller between 2 or more reactors (one face touching each reactor) for multiple reactor control (and yes, if ANY reactor hit the temp setting it'd trigger the controller. "all for one, one for all" kind of thing.)
Basically you are converting the Reactor Controller from a simple on/off switch to a "controller" by converting it into a sensor, which then can be used in more advanced setups to give more precise control.
You could then connect 2 (or more) controllers up to a reactor, 1 could be set for MAX temp the other for MIN, then with a user designed circuit you could control the reactor so that it would stay between the temps set.