First of all, welcome to the ProGuard Community!
Regarding applymapping and flattenpackagehierarchy/repackageclasses;
-applymapping can be used together with repackageclasses. It should normally not be ignored. Did you provide a path to the mapping file and a new package name.
Can you share your configuration file or a sample?
Regarding obfuscation of enums;
If the enum is not accessed through reflection, you can obfuscate it. If it’s accessed through reflection, then you must keep the name in your config.
If the enum is shrunk away (but there’s no issue with reflection) you can use the allowobfuscation keep modifier. This specifies that the entry points specified in the -keep option may be obfuscated, even if they have to be preserved otherwise. That is, the entry points may be renamed in the obfuscation step, but they may not be removed or optimized.
You can read more about this here:
And then cmd + f for “allowobfuscation”
If you can share your configuration and perhaps a small sample, we might be able to help determine why the -applymapping directive is not being applied for you.
If you have already done so, I suggest using the Proguard Playground when possible. It will allow you experiment with different -keep options to see their impact ahead of time, without having to build. This saves lots of time and effort.
Please let me know if anything is not clear.