Pablo from Angle here, we’re the team behind the Merkl solution.
While this is a proposal from Gamma, I want to stress as @BP333 put it that the Merkl system enables to put in parallel different active managers, and any active LP manager can be supported within the system.
Contrarily to other usual one size-fits-all incentivization solutions on Uniswap V3, Merkl still leaves a full flexibility for LPs to provide liquidity however they want.
Merkl is also a non custodial solution, in the sense that it bears no liquidity risk for LPs. You don’t need to stake your liquidity anywhere to be eligible for rewards, and so there will be no smart contract risk for LPs. UX for providing liquidity and being eligible to the rewards will be the same.
With this, using the ARB airdrop to incentivize liquidity on UniswapV3 will be a nice way to try to increase liquidity on the pairs which are yielding the highest Volume/TVL ratio and increase Uniswap leading position as a DEX on Arbitrum. While I agree with @BP333 on the pairs important for the ecosystem that are mentioned, there might be other pairs on Arbitrum which are not incentivized so far, are yielding a super high volume even with a low liquidity.