Found those in my stash, just tried to see if they would work with rpi-rgb-panel.
Of all address types, 0 is the closest one and after trying them, -led-multiplexing=4 is the zaggiz multiplexer that works
root@DietPi:~# ~/rpi-rgb-led-matrix/examples-api-use/demo --led-slowdown-gpio=1 --led-rows=16 --led-cols=32 --led-show-refresh --led-scan-mode=0 --led-row-addr-type=0 --led-panel-type=FM6126 -D0 --led-multiplexing=4
Obviously the pixel order is off but that’s fixed with –led-multiplexing=4 . Here is a 64x64 array next to a much smaller 128x128 (P1.875)
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I should have added that people with pixel mapping issues should try all values of
–led-multiplexing=<0..17>
… or construct your own versions, as I described in issue #1725…
correct, if none work, then a #18 and #19 and so forth, will be needed 
I just forgot in the past to remind people to try the existing mappers first
I have a method to simplify this process… I tried to demonstrate it in action in #1725, where three users reported problems with mapping. Unfortunately, only one of them tested it on his panel…
I failed to properly test it, it works fine with -led-multiplexing=4 , I just updated the post
It’s very bright indeed 
The only sad thing is I have another 16x32 1/4 scan that looks very similar, but its mapping if of course totally different, so I can’t use them in the same array
On the plus side, I’m seeing 1600Hz refresh rate
