Slow: save Pots of Gold by not upgrading level 3 and 4, and use PoG for the end game chests. to get that 1 Druid upgrade, do that 3 times, and all you need is 3 upgrades from the tasks.
No;my slow way it was this last year :
-have festival and shipyard at level 3(and hat factory at run 1 or flowers factory at run 2) and the others at level 1 or 2 depending the run
-open in 4 runs all the 6 chests but you will still remain with +1k pots available from quests, so you can do another 2/3 runs depending how many pots you have gained from incidents without opening another chests unless the free chest
-it will necessary do 34 tasks at run 1,34 tasks at run 2 and 32 tasks at run 3
I had done in live server 5 runs and start the 6th having 168 tasks complete and I needed only 7 tasks to gain an another upgrade
At the end I got 11 pieces without problems
I think in either system never complete all tasks, correct?
This is correct; none of 2 ways will complete all the 38 tasks
Fast: Use the PoG's to level up buildings, and no chests, and do Tasks quicker get more Druid upgrades from the Grand prizes, stop around 25-28 quests then complete.
you have a lot of time for the event?if yes,then you can choose this ways and in addition,you have more "micro-rewards" obtained
probably tomorrow I'll go at run 3
https://prnt.sc/wkgvx2 and I'll remain for +1 week