Would be nice to install Netdisco as web app only, or Poller Daemon only. One use case is where we don't have net-snmp around for compiling the perl bindings (e.g. have this problem on the Heroku demo site).
One way would be to use the cpanminus+Module::Install "features" feature. It's disliked by some, but seems to work well. Another way would be to have a set of metadata-only packages which specified different sets of dependencies.
What I think important is that the simplest thing does the most obvious - i.e. Installing App::Netdisco gives the whole shebang. Then there is some way to explicitly say "web" or "daemon".