Just stating my opinion here, not criticizing if you choose to do things differently.
It's wasteful (inefficent) to allow stuff to be copied to $work_dir, then do double-work to remove it.
It's a PITA to chase after "editing/tweaking the snapshot script to customize it" each time a new version is released.
The script consults an excludes list. Customize THAT.
apt-get purge lahdeedah...
First of all, nowadays (for the past year or more) we can just type "apt purge..." or "apt install..."
("apt-get" is passe)
Second, in this exact instance, purging the package may not cause problems, but many of the things I'd weed(exclude) from a snapshot
would cause dependency breakages. Besides, sometimes an entire package isn't unwelcome (for me), I just want to avoid
copying selected cruft files I'll never use (cruft which eternally adds unnecessary overhead to "toram" live sessions when using the resulting snapshot).
That's the backstory for my "just whack the files and let apt/dpkg go on believing suchandsuch is still installed" remark, above.