Thanks for the extra info.
They are correct in the fact that if they’ve opened up other projects the shaders will already be compiled. (But this is also per engine version, so if they haven’t opened a 4.10 project in a while a shader recompile could be triggered)
I’d ask the reviewer to create + open a 4.10 project first to be sure any engine shaders have been compiled before opening your project.
I’m having trouble imagining any reason why a project with just audio files in the content folder would compile shaders. The only other thing I can think of is if there is a a project setting changed. (For example, if forward rendering was enabled or Mobile HDR turned off) But since you said you tried with a newly created project I’m doubtful this is the case.
To be 100% sure you can compare your projects Config/DefaultEngine.ini to a DefaultEngine.ini of a newly created project.
Using an early version of UE is best for compatibility, but if you are unable to get past this roadblock with the reviewer I think submitting a 4.16 or 4.18 version of your assets could be worth a try.