the Pro 11 2nd gen should be tier 3 and this could lead to wrong assumptions.
I tried to debug the library but I don't know what to check, I've printed some data from deobfuscateAppleGPU() method (console logs and screenshot below).
I also tried to run GFXBench Metal as double check, and I get a different GPU chipset from the one I get from detect-gpu
[Log] pixelId – "80162181255" (index.js, line 185)
[Log] renderers (index.js, line 236)
Array (11)
0 "apple a8 gpu"
1 "apple a8x gpu"
2 "apple a9 gpu"
3 "apple a9x gpu"
4 "apple a10 gpu"
5 "apple a10x gpu"
6 "apple a12 gpu"
7 "apple a12x gpu"
8 "apple a12z gpu"
9 "apple a14 gpu"
10 "apple m1 gpu"
[Log] chipsets (index.js, line 237)
Array (11)
0 ["a8", "8016218135", 15] (3)
1 ["a8x", "8016218135", 15] (3)
2 ["a9", "8016218135", 15] (3)
3 ["a9x", "8016218135", 15] (3)
4 ["a10", "8016218135", 15] (3)
5 ["a10x", "8016218135", 15] (3)
6 ["a12", "801621810", 15] (3)
7 ["a12x", "801621810", 15] (3)
8 ["a12z", "801621810", 15] (3)
9 ["a14", "801621810", 15] (3)
10 ["m1", "801621810", 15] (3)