"Shopping Spree" Weekend Quests

You've said it better, using power feed on long time stalls should award one coin purse each time but you have to wait the 5-6-7-8h+ for it to harvest after using power feed. With a harvest time of 8h, you can do that 3 times per day. 44 stalls can be put down on both fields (88 total). 88 stalls x 1 power feed each x 3 harvests per day = 262 power feeds for the entire day for up to 262 coin purses in 24h (no garanty that you'll get a drop from each stall). To get enough drops, this most be done on a second day.

Doing just one full round of breeding (132 breedings) x 2 power feeds = 264 power feeds for 264 coins purses (assured drops). Even with no pheromones, a full round of breeding is 5h. To complete the event another 110 breedings are needed, which means one new round of breeding in 5h max.

Result:

power feeds on stalls: almost 2 days of harvests with no sure way to get all the drops
power feeds for breeding: between 360 power feeds (180 breedings) and 484 power feeds (242 breedings) in max 10h, with certainty to have enough drops. Bonus: no ripping on the Main farm and Green Meadow. Win-win I'd say!

 

I just finished the event. No breeding, no power feed, no gold slot speed boosters, just +100% harvest from stalls to give more animals.
There is still some stalls (neon cats, neon hamsters, red yak, bernese etc) to be harvested before I go to sleep. I would say 10-18 h animals are good enough to get drops after start of event. I had even quicker ones occasionally. Before that it is good to have longest ones ready to be harvested when event starts and change them to quicker ones.

I have no problem using main field or green meadow, they are usually just for crops and easily changed to anything else.

 

Edit:
Done and dusted.
Got CR up and running.

 

I think for me, this go round, using the critters and a 100% diamond harvest, got me lots of stock for some future event/ quest where we need to donate critters. If I'd had time to look at what breeding quests I could do with current stocks, that would have been a good way to go, but alas, that was one rabbit hole I wasn't willing to go down...RL has a way of getting in the way!