Jumping in to mention that Angle built a Angle Labs built a Merkl distributor for rewards distribution to Uniswap v3 LPs and have been using it since August 2022.
This was already mentioned by guil-lambert (here).
Merkl could be used to let other protocols distribute collected fees back to holders.
For your information, Merkl gives extensive control to protocols as it allows the customisation of the distribution to favour active liquidity and/or LPeing of one token in particular (e.g. protocols could easily allocate 50% to active liquidity, 10% to Token A and 40% to Token B). Also no staking contract is required and no LP funds deposited on Merkl.
Sharing the Merkl beta (1) claim page for LPs, (2) deposit page for protocols, and documentation.
Please feel free to reach out with any question or ask directly here. This has helped us solve the distribution problem to Uniswap v3 LPs and we’re willing to make this a part of the solution here