This was, unfortunately, another event I could not ultimately complete. While I found the recipes to be interesting and the search for the Gnome was not an issue (I have a clear enough understanding of my farm's layout that I knew where to look), the biggest issue--for myself and for many others--was the poor drop rate for various items. In my case it was the Spore Sprout from deliveries and Portobello from the pigs (when I finally unlocked it, the Chanterelle I was receiving from the Maple Trees would have been sufficient to have completed a second Terrarium and the recipes for all the extra recipes needed for the additional Gnome coins). Also, the Soft Moss from the Mine and the Iris from the Fishing Pond were not difficult to obtain. However, with Porcini and Portobello being in such high demand for everything, the poor drop rates very much hurt my progress and prevented my successful completion of the event.
Feedback and Suggestions for the future...
1. In the past, events that required extensive crafting sometimes had everything that was crafted paid for the final goal. It would be nice if all goal events were like that. However, this event, though it started that way, required us to repeat the crafting requirements an additional 4 times (9 times if a player hoped to get both Gnomes). Had the final requirement for the Gnomes been less--say, 2 coins instead of 5--it may have been more bearable with the drop rates being what they were.
2. Perhaps, if the drop rate were not altered, a different vector could have been selected for the drop of the Portobello, perhaps via harvesting one of the mid-length harvest time crops. Had this been the selected option, the drop rate could have remained the same and players would still have had a reasonable chance of collecting enough Portobello to achieve success.
3. Alternately, perhaps instead of each collection from the Pigs having the chance of dropping 1 Portobello, perhaps this could be randomized to drop either 1 or 2 (or perhaps up to 3) at once, with 1 being the most likely, but with the occasional 2 (or 3) being dropped. Similarly, drops of Spore Sprouts could be likewise randomized.
4. At the end of any event, perhaps Mr. Merriweather could be utilized to help players dispose of event items. It is interesting that, during events, he does ask for some of those items (I remember it happening on my farm during the Sweet! Cake Pops! and I think perhaps it also happened during the Rock 'n' Roll World Event, but I'm not sure) but once the event ends he stops asking for them. If perhaps during the next few visits he happened to ask for event items, it would make it easier for players to clear out all their unusable items all at once (since Mr. Merriweather is able to accept more than 10 of one item at a time) rather than putting everything up for sale in lots of only 10 and then discarding it. This would have the added benefit of encouraging more players to expand to the Balloon Dock and make greater use of Mr. Merriweather.