For BTC2-FLI, I would say that the Onsen rewards are helping the pool maintain depth and I suspect we would see less AUM in the pool if the Sushi rewards stopped. Infact, I would say that without Onsen, BTC2-FLi would be short of liquidity.
I would certainly agree that the current rewards are not enough to grow BTC2-AUM. However, we know LM is a poor (/expensive) tool to grow AUM. More detailed analysis of the daily / average volume and comparison to the issue and redeem volume may give us a better idea of what is happening.
One thing to remember is we don’t expect AUM to grow like the sector products, we would expect the leveraged product to grow units when people are bullish and reduce when people are bearish. In a prolonged bear market, AUM will trend to zero, and I personally see no problem in the liquidity doing the same.