(put XML file in LMC8.4 folder at the top level, then double tap next to the shutter button)
If the viewfinder does not freeze after a few seconds, you have loaded the config file correctly....
Oh, and a second way, if you have the config loaded and you take a picture, the file will have LMC8.4_A52s_Metal
in the filename if you have the config loaded.
To make it more concrete, if you go to Settings|Stream Configuration|Main Camera, and you see several values set to 61448 (and you did not change them yourselves), then the config file was loaded because by default those values are not set that way I think.
Put .so file in LMC8.4/libs folder in the top level directory, then go to Settings|Photo Processing|Library|Lib From Dir
You select the library there. If you can select it there you have probably set it correctly.
View attachment 5774093
The difference with or without XML config is massive, but of course you can only see that when you compare images. But I could not see a difference with or without the .so file.
So I would say that is an optional step, and that is why I did not include in my earlier comment (but I do have that library set myself, just for completeness).
Also, I think there are newer config/ lib files from 'Metal', but I always like to link to stuff I have actually used.