I have seen many complaints regarding the drop rate of boxes from Ressource nodes and possibly barbarians as well and was interested to test it out myself. Being in the fourth day of the event now my opinion is the following:
1) The drop rot from ressource nodes below 250K did in fact decrease significantly. Level 1 non-stop farming is no longer a viable option.
2) level 2 nodes (food and wood only) have the best time-to-box value from a farming perspective. Occasionally you will come back empty handed but in general you will receive a reliable influx of boxes in a reasonable time
3) no change in barb drops when all you do is your automatically recovering AP, which is the only AP I spend on it
4) the drop rate from Ressource Production in your City is the ultimate best option to gather ressources, with node farming and barbarians only to be used as a complimentary method.
4.1) every 4-5 minute you can collect all four Ressource types in your City. Typically you will get 1 box for it. Occasionally (rare) you get nothing, but that is just bad luck. Tip: collect all ressources, wait for them to re-appear, then close the app and restart it, then collect them after it loaded anew
4.2) if you wait anywhere between 10-15 minutes the box rate increases to between 2-5. So when you are away for a couple minutes and can’t collect the ressources every 4 minute you will still get a potential good deal when you come back after 15 minutes. Occasionally however you will not get any box at all. Tip: make sure to have cleared all your received boxes every time so that your inbox as 0 before you collect
4.3) the old tip of waiting 30+ minutes is no longer the best sweet-spot to city collection as the amount of boxes also will only add up to a max of 6-8, which can be eclipsed by 4minute or even 10minute collecting.
4.4) getting 250+ boxes a day through city collecting, level 2 farming and regular AP harbing even with rather significant breaks (assuming an office job where you can’t be online at all times) is easily possible.
4.5) opening 100 boxes a time results on 150-180 letters. Enough to finish the event on day 5 easily or if you like, day 6
Conclusion: typically a F2P approach to this event was to have the game run at all time and spam lvl1 farming and once every half or full our collect an additional batch in the city. The General idea of having the game run at all time remains unchanged while the method to get boxes switched. Now city collecting will be spammed with lvl2 nodes bribing in supplementary boxes every 20-30 minutes.
The event remains the absolute best and easy way for an active (similarly active than before) f2p to net 35 legendary sculptures without having to pay a single penny on the third stage.