MK14's results:
l_id1: i(d1)=-5.56678e-009 at 0.5
l_id2: i(d2)=4.80122e-005 at 0.5
l_id3: i(d3)=0.00111349 at 0.5
h_id1: i(d1)=0.0010563 at 1.5
h_id2: i(d2)=6.44745e-005 at 1.5
h_id3: i(d3)=-4.80829e-011 at 1.5
t_id1: i(d1)=1.67117e-005 at 2.5
t_id2: i(d2)=0.000742218 at 2.5
t_id3: i(d3)=1.66234e-005 at 2.5
Low I(D2) is 48uA - not too great for the off state, and its on state Tristate I(D2) is only 0.74mA vs approx 1.1mA for the others.
You are right, but..
When I came up with the circuit design (tonight), it was intended for there to be red LEDs (or similar, somewhat sharp voltage cut-off LEDs).
The datasheet, seems to show that the current (and hence brightness), falls sharply, from around a 0.5 volt drop (from around 2V full brightness 20 ma, down to less than 100 microamps (and less), at around 1.5V to 1.6V. According to the (typical) graphs. See page 2..
https://www.vishay.com/docs/83171/tlur640.pdfMCUs, tend to be 3.3V (or lower, at least internally), rather than the previous 5V standard, these days. Which would be needed, to avoid the lower voltage red LEDS, from turning on (D1 & D3), because of the voltage across them in my circuit.
tl;dr
I haven't tried it. But, Red (i.e. around 1.8V to 2V Vf LEDs, but Green or Yellow, should work as well, as long as NOT the later, higher voltage types) and 3.3V supply, should allow the diode drop of the transistor B/E junction, to NOT turn on led D2, too much to be annoyingly visible, when it is suppose to be off.
At some lower led drive current, the led will/should appear to be 'off'. The datasheet doesn't seem to mention what current/voltage that is.
Modern ones, tend to light up, even with tiny currents. But the (considerably, now obsolete) older ones, tended to (at least in some cases, especially with really cheap ones) turn/appear off, at lower currents. If I remember correctly.