I think in your case a bigger reservoir would have been the only change needed in your setup to allow you more time away from the plants, that and maybe raising the lights a little bit extra if you know you would be gone for awhile.
My plants are in their own 5 gallon buckets, no rdwc, but I have been experimenting with using 10 gallon rubbermaid trash cans as a reservoir/bucket and it makes a big difference. In the 10 gallon even with a very large plant at full size (covering about 8 sqft and nearly 6ft tall) I can still go about three days before the water level gets dangerously low. I could switch entirely to the 10 gallons and cut my workload nearly in half but at roughly $30/each vs $3.50 for the 5 gallons and with over 24 plants its too big of an investment for me right now.
I'm just saying the work load can depend heavily on the setup. For example, and I know little about coco so correct me if I'm wrong, but from what I can tell it needs the most attention if you are watering by hand, at the same time it seems like if you automate the watering its no longer very work intensive, all just depends.