Thanks so much for you kind words about the thread, very much appreciated.
Firstly, about Banggood, I've been ordering from them for years and have never used anything other than their free shipping with no tracking (other that what they provide on the website) and no insurance. Nothing has ever failed to arrive. Once, an item arrived broken and after I sent a photo they promptly sent a replacement. The problem with Banggood is in the past they have had a prosperity to sell goods that they claimed were in stock but turned out not to be. Then you would get charged for a back-ordered item and could get stuck waiting for a product that might not show up for a long time. I even gave up ordering from them for a long time because of it but decided to try again and they seem to have dramatically improved how they handle things. Over the last several months I've ordered multiple items from them on several occasions and each time when an item page said it was in stock the parcel was shipped the next day with email notification and arrives like clockwork in 16 days or less here in New England. You can order from them with confidence. Also, they now have a presence here on DCT so if something goes wrong you can get help here plus they have their email customer service on the website. If ordering low cost items, insurance is probably not a worthwhile investment anyway and to me it's always been worth taking a chance. Many Chinese vendors try really hard to do a good job and provide good service even if they drop the ball now and again.
As for IR cut filters, I'm still exploring the possibilities, so I'll have to get back about that. With this varifocal lens the rear element will probably require a 9.5 to 10mm IR-cut filter. The problem is that the rear lens element is deeply recessed so installation or removal will be tricky and I'm still devising a strategy. eBay has some decent low cost IR-cut filter options (mostly from China). Truth be told, I'm having so much fun with my color balancing mods, the IR cut filter has been on the back burner for now.
@dirkzelf's videos look pretty cool! How could I have missed those? As for my recommended settings they would work to a degree for the video where the default color is magenta, except the settings would need to be tweaked for his particular lens.
As for the black and white footage, obviously the camera is set to B&W so none of my recommended RGB adjustments would have any effect at all. The sharpness and contrast settings would have an effect but they might not be appropriate for the B&W setting or this particular lens. If you want to shoot B&W like this you'll need to experiment. The saturation setting would not likely have any effect on a B&W image either.
Finally, I would start by ordering just one of these lenses and see how things go and then perhaps order another one later once you see what it can do and how you like it.