In Interface 2, it says: When sandbox is used with -k option, it will
delete .o and .e files from hosts. Going forward, deletion will
happen only by using “-R” option, not by “-k” option as It is not
expected to delete using “-k” option when it stands for “Keep_Files”.
I believe that what has been confusing everyone is that the original
coders chose a confusing name when they used “Keep_Files”. The -k
option is not about preserving files, it is instead about preventing
files from following you home.