I did definitely mean quicker for targeted materials...
Example...
I want ruthenium...
I go to eddb.io, and I go to bodies, I put in ruthenium, pristine reserves, metal rich body (cos they are close to stars and almost always have volcanism), and the optional field I put volcanism, so I can immediately ignore any results that don't have it.
Then I start clicking on candidates I like. If I see one that has Ruthenium and Technetium, I ignore it and keep looking until I find one that ONLY has Ruthenium from the Grade 4s. As mentioned before, this ensures that EVERY needle crystal, without exception, drops a ruthenium node.
Since I've already picked out suitable planets for the majority of G4 raws, I don't have to do the mapping any more, so I take that out of the equation for 'time spent'. What makes it efficient is that you just park your ship, get in the SRV and do a search pattern, while constantly watching the left (contacts) panel for needle crystals (I often try to get a body that has G3s that I want as well, like tungsten and cadmium, whcih are often found together, so I also go for crystalline clusters), when I'm pretty confident I got all the needle crystals at least, it's back to the ship and take off and go to the next site. Since they aren't often far away, it's not too bad on time to take off and land again, you don't need to leave orbital flight to do it, and it's kind of a fun game to see how much throttle you can use and not overshoot the next field.
As you find bigger and richer fields, you'll make a note of them on a bookmark, so in future you can go striaght back to the rich fields.
Once this legwork is done, it becomes extremely efficient. I'd say I get at least 4 needle crystals from small sites and as many as 10 from large sites (but they take longer to search, naturally. If you ask me, this is an exactly perfect mechanism in terms of how to get what you want (wihtout fail!) and with reasonable effort/reward ratio.