Something that came to mind. For Best use of resources, wouldnt it be best to use gems to speed craft keys from Eveline? Think about it. 25 gems and you can have a key to open a chest, which is cheaper than spending outright gems to open anything. Seriously, 30 gems to open a wooden chest and 25 gems to craft a wooden key at the minimum from eveline. You should come out ahead to spend all your Ore to speed craft keys, open chests for more ore, and use that to speed craft more keys.
Which should net you a good loop and a ton of resources using this method.
This all depends on how you value gems. Currently there are a finite number of gems available to acquire (about 28k from doing 5 playthroughs and all associated sidequests). The only ongoing sources of gems (excluding VIP and BattlePass considerations) are:
10 Gems / Day from Shop
45 Gems / Week from PVP rewards (x3 for doing all 3 Tourneys)
0-500 Gems / Week from PVP Leaderboard (I suspect the average player is getting somewhere between 200-600 Gems / Week
So once you have exhausted your finite supply, you only have 500-1000 Gems / week to spend. Given that you can buy x50 minor shards for <20 gems in the shop (limited to the offers daily of course) or other types of bulk buys, I suspect that this is ultimately not a good gem value. Until Eveline is mythic, you will likely generate a lot of wooden keys; the main resource from wooden chests is food/ore/gold which are all now available in relative abundance, so you are in effect trading a finite resource for infinite or at least more abundant ones.