I'm cleaning up my AliExpress basket and I get an idea:

Double down and get even more squares into this T^2 tech. 

30cm * 3.14 / 2 = 47cm, which is 2cm longer than 3 * 15cm. I can have the 3 white ones on the front of the cylinder tube and the 3 black ones on the rear of the tube where there's a mouth cutout. (I haven't modelled it in yet, but I'm going to keep most of the acrylic tube intact and just cut an internet browser tab shaped cutout so that I can eat.)

The reason for putting the black PDLC on the cutout side is simple: air quality is less of a priority when I'm likely to use it. I'm less likely to be doing intellectual work and more likely trying to get an IMAX cinema vibe going if I desire a black PDLC behind the virtual monitor. If I am doing intellectual work and I still desire a black PDLC , it's likely that it's because I'm working in the fresh outdoors (away from pollution sources) and want to improve contrast since the outside world is much brighter.

With 1 square infront and 2 on each side, I should gain some quality of life improvements. 

The main one is an animation that turns on the centre PLDC and then turns on the two side PDLCS 0.33 seconds later. (Remember, turning the PDLC on makes it transparent.) This animation would also be used in reverse and makes it much more comfortable to switch from full transparency to full mist and back, compared to suddenly switching one large PDLC. My instant thought was "Wow that's certainly some Iron Man Armoured Adventures aesthetic!" but all I can remember is a void of darkness whenever the camera was looking at the suit wearer. Honestly, the only instance I can think of where I've seen this UI/UX is in Total Fantasy Knockout where the control room metasurface of spacelike sparkles opens up to a view outside:

I also would have the opportunity to only mistify the front PDLC for contrast and keep my peripheral vision transparent, or have things the other way around to feel like I'm in some frosted glass office of the future (and hide distractions). I could also have a slow "mexican wave" animation to get the Thunderbird 5 rotation vibe I've mentioned in a log a while ago without physically moving the acrylic tube. Like the video below but rotated 90 degrees, way slower and much thicker strips:

Oh and I just noticed that the acronym is PDLC not PLDC. Now I have to be on the lookout for that typo.

To conclude, I think this white and black PDLC film idea is a good solution to the problem of high light sources behind the screen. Using a polarising light gate (1 pixel LCD w/ no backlight) would only work for flat surfaces, won't cover all the vision, blocks 50% of all light in the most transparent state and only comes in specific sizes. Dimming electrochromic film takes a while to switch (which isn't really a problem in this application) but I can't seem to find any on AliExpress (which is a serious problem in this application).

PDLC seems to have a number of benefits:

Seems that full transparency requires 4W * 0.45 * 0.15 = 0.27W of power. I also like the sound of the safety as I don't want acrylic flying if I trip+fall. Putting the film on the inside might also be a consideration, since 29 * 3.14 / 2 = 45.53cm and even closer to the length I need, so the film could be completely gap free all around and reduce exposure of the film to the elements. Yeah lets go with that plan instead. 

Man, this is turning out to be a very cool helmet. Fairly expensive tho... but very cool.