Opalec NewBeam with Out-Tec Flashlight Tuner

Just got me an Out-Tec Flashlight Tuner from Germany to play with. I must say I'm quite impressed with the quality, despite the bare aluminium finish and am eagerly awaiting the darkness.

My GF's unmodded Mini-Mag is in her car at work, so I'm testing it with my Opalec'd one. It works fine, but I notice that when I switch from Opalec to Out-Tec with the rotary switch on the Out-Tec, that the LEDs only come on dimly and the Opalec remains faintly on.

I've cleaned all accessible contact surfaces and get the same result. I assume it's something to do with the Opalec electronics. I don't regard this as a big problem, full Out-Tec brightness can be restored by "resetting" the Mini-Mag, either by turning it off and on again at the head, or by striking it end-on into my palm.

I recall there being a laser pointer tailcap for the Mini-Mag, which was not recommended for use with the NewBeam for some "electronic" reason. Would the same apply here ?

The Flashlight Tuner is supposed to be used with the original incandescent bulb in the Mini-Mag. When you put it in a light with a New Beam (or any other LED retrofit) in it, the resistance from both devices in series with one another is too great, so BOTH devices malfunction.
Both the New Beam and the Flashlight Tuner have some kind of circuitry in them, so when you put them in series on the same power supply (two AA cells in this case), both will malfunction in some way or other.

Recommendation: put the Flashlight Tuner on a Mag that has a standard incandescent bulb in it, and put the New Beam in a Mag with a regular tailcap on it.