Thanks @dr-stone for sharing here these concerns and possible mitigation.
For the idleRAI pool, Idle protocol is managing most of the lent assets, with the ability to further optimize the utilization ratio. The algo is now able to increase the overall market returns and all the lenders can benefit from it.
The mechanism that @ghost has described is true and the concern is definitely valid.
The issue is not Cream as a lending source, which has been approved following our Integration standard Requirements and has a risk profile similar to Fuse.
A future algo improvement might consist in enabling the holding of unlent funds if the returns can be higher; this would further reduce the risks while continuing to maximize the profits.
In the current circumstances, the proposal to remove Cream from idleRAI seems an actionable plan.