I discovered "unlimited" faction shards & gold chests. Drop a heart to show some lovin 😉
HA= hacked app, NV= normal version. These are used to clarify which is used in each step
1, HA--this requires that you make it to an uncompleted floor in the faction tower that rewards shards AND the chest
2, HA--using hacked app, play the level, claim victory, then return to kingdom asap before the sync error pops up
3, HA--while in the kingdom view, make sure the gold chest spawned before sync error popped up
4, HA to NV--close the HA game and re-open with normal version, while at kingdom view all coins will properly be given
5, NV-- the gold chest AND shards should be in your inventory
6- NV to HA--close the normal version, re-open hacked version and repeat the level and steps. You'll notice that the level isn't marked as completed.
Note: this worked >10 times for me until I accidently completed it on the normal version (my fault). I have only tried this with 1.5.8 because 1.5.9 isn't out yet. Let me know how it works out for you! As mentioned by @ABSOLUTEHACKS the sync error is likely caused by the coins and you need this error.
Happy summoning 😉