I believe (without the ability to confirm at this moment) that Vr, however determined is defined as the speed "below which the pilot shall not apply the control input intended to raise the nose wheel clear of the ground" or similar. this means is used during demonstration of compliance with the certification basis and is consequently the only specified method of take off procedure that is supposed to be used.
This of course ignores multi tailwheel but that is another matter altogether.
there is in fact no direct civilian equivalent of a 'tactical STOL' take off as the performance section of the AFM defines the performance and conditions that apply to obtain the maximum certified performance as demonstrated by the TP during demonstration of compliance. The true name is a performance take off and whilst some company SOP's have wide ranging interpretations of STOL procedures, these are usually dated and do not fall within the certification conditions. some PNG ops for instance.
Be careful when operating any aircraft outside the design cert limits, you are the TP now.
I also have a 5 figure total (for what it's worth) and Ag and FT exp over 35 years and the older I get the less I stray outside the defined specs, some of which I have proudly been responsible for defining.
I also ride a motor cycle and despite 35 years on them I still know that it will be something that is outside my experience or that I just didn't see that can get me at any moment.
Vmca applies when the aircraft is still on the ground as well as when airbourne, so take care.... I have lost engines on T/O in M/E tailwheelers and that isn't fun at the wrong moment, also had brake fail on landing in similar. At those times a nose wheel on the ground seems like a good idea.
HD