Can I make a suggestion? How about a new resource called loyalty earned by time spent in the game. The resource is not tradable but allows for upgrading rarity or rerolling buildings. Each claim earns like .1 loyalty.

Use .1 loyalty to upgrade or reroll stats on a common building.
Each rarity requires 5x more loyalty to upgrade or reroll stats.
So uncommon needs .5 loyalty
Rare needs 2.5 etc.

While loyalty can't be traded, the items can which gives players something to work towards and another potential revenue stream for alt accounts who are willing to put in the time.

Also, I feel like attack/defense formula needs to be redesigned. Top player can be untouchable and produce enough Denar to maintain defense to never get attacked and keep pumping out insane Denar which can tank the market if he wanted to. In Denar, ori, or buildings. Rework attack to be a percentage chance to win while only needing 50% of the defense to have like a 10% victory chance then scaling up. To 100% chance with a 110% offense to defense ratio. This will at least help make Noone untouchable.

Rework the denar production calculations. Trade power seems too powerful.

Sell another chest for ori that removes common, uncommon, and rare options. Spreading the possibilities among the higher outcomes. Costing like 3 ori each.

With splinterlands new set coming, doing a promo event where you sell something in game for Dec or sps or vouchers could be interesting. Maybe add a new chest /item slot for a limited time that gives generals who give only military stats, no econ stats. Or maybe 1-10% boost to a stat or 2.
Those are my suggestions. Enjoying the game so far. Hope it continues to grow.

Loving the game so far. Hope it continues to grow!