I have never used ExtUtils::MakeMaker before. I had heard of it in passing but had not looked into it until you posted about it. Right now I have not even created the distribution directory yet.
As for naming, I wish I did not have to use the word "slurp". I have an irrational bias against it, but I will probably cave and use it since it appears to be the common way to describe what this module does. I posted on PrePAN and got the suggestion of File::Slurp::Affix, which would make the subroutine name slurp_affix. I will miss the word Fancy. However, I guess I should not introduce a new namespace with my first module release.
My OS is Debian 10 (Buster); my perl versions are 5.28.1 local and 5.16.3 or 5.30.0 on web host depending on the shebang.
No matter how hysterical I get, my problems are not time sensitive. So, relax, have a cookie, and a very nice day!