I think this is a good idea, multiple tiers allow to reward different stakeholders. If we only had one tier rewarding users, we would miss out on attracting / rewarding those who hold more tokens. It’s important to show appreciation also to larger stakeholders.
I don’t worry about users “gaming” the system to receive the subsidies - the subsidy anyways only affects the gas costs, not worthwhile to cheat (+ cheating costs would be high on mainnet).
Always good to see ways to bring utlity for governance tokens. Also like the idea of having set parameters that govern the use of the fee discount and having a set amount form treasury to cover these expenses for a set amount of time.
Couldnt one just us a flashloan to game the discount system every time they wanted to make a trade? Could we bake in a mini-vesting period of needing to have acquired COW no more than x blocks prior to the trade, preferably at least 24h worth? Or some other duration that at least requires some exposure to COW.