Expand "Compare" feature for archives when copying files

[Sektor]

When copying file to another directory and if file in that directory exists, I have option to compare these files (More Options -> Compare). For now this option appears only if I'm copying "naked" file into also "naked" file, i.e. file(s) being not in archive(s).
It'd be welcome if "Compare" feature would work for archives, too:

1. When copying file into archive
2. When unpacking file from archive into folder
3. When copying file from one archive into another archive

[petermad]

Support ++