I’d be glad if someone would share links to aliexpress/ebay or other Chinese shops where you have bought rgb led panels and they work with this library.
This has been my preferred supplier to date.
Shenzhen Coreman Technology Co., Limited
https://s.click.aliexpress.com/e/4rBFpwMo
Thanks!
What scan rate are you using? They have 1/2, 1/4 and 1/8 scan.
I’m only buying 1/32.
I’ve been buying from Azerone, they have been very helpful to me, and either sell from amazon, or I send them a message on FB, paypal them money and sell to me direct (from china).
You can friend him/her an FB and/or send DM if you need something not on amazon.
Thanks!
Do they know about this library and what type of panels work with it?
They somewhat know about it since I’ve worked with them on testing panels, but they don’t have the library or a way to test for you.
However, they can check if the panels have FM6126A chips and avoid those, and you can tell them you only want ABCD or ABCDE panels, not AB or ABC.
It’s not a full guarantee, but better than other vendors I’ve worked with.
Also, if the panels are on amazon prime, you can just return them 
I ordered 3 32x32 panels from this store and they worked perfectly. I have also used Azerone as mentioned by marcmerlin.
https://szlightalldisplay.aliexpress.com/store/228842?spm=a2g0s.9042311.0.0.347f4c4d9uvfl4
About AB and ABC panels (which really are AC panels, B is not used it seems), they do work with rpi-rgb-led-matrix/ on rPi, so if you get stuck with them, you can now use your arduino code on them thanks to the hack driver glue I just released (lightly tested, but it should work for others than me hopefully)
Any new sources of panels?
I need P10 outdooor panels, but nothing I can get locally seems to work 
Try contacting azerone, to see if they can help https://www.amazon.com/s?i=merchant-items&me=A1QIWERAQGCBKO