Anyone tweaking Legacy smoke units???

Short answer - no need to tweak them.  A lot of people adjusted the TMCC smoke units because of the very low output of smoke.  I had several TMCC engines where you struggled to see anything coming out of the stack.  After doing the mods, it greatly improved the smoke.

With all my legacy engines, you have 3 levels of smoke.  I have tried high, ONCE, on my son's visionline Big boy.  It fogged the room with just one pass of the layout.  I normally run in low or medium at most.  I have no need to modify the legacy smoke units.

The only issue I have ever read was to adjust the thermal sensor.  In some early legacy smoke units, the thermal sensor was too close to the heater so not much smoke was produced.  Just slightly bending the sensor away from the heater fixed the problem.

No need to fix something that isn't broken.

What Joe said.

I've never modified Legacy smoke units for smoke volume, other than fixing stuff that's incorrect/broken.  As others have said, most Legacy has sufficient smoke.  Obviously, things like new wick, tightening the screws on the smoke resistor, and adjusting the thermistor are in the incorrect/broken category.