When planning Ops that require many keys for a particular portal, I find farming these keys can take a very long time, for example:
- capture the portal
- drop any existing keys for that portal (or pop them into a capsule)
- hack the portal
- wait 5 minutes for cool down
- do steps 2-4 again until burn out
Which will get me 4 keys in 20 minutes.
Obviously I can add a heat sink to speed up the cool down, but what is the most efficient way to farm as many keys as possible in a short time (say 30 minutes or so)?