When the DSR (Dai Savings Rate) was introduced by MakerDAO, the Compound team developed a CDaiDelegate to take advantage of DSR (pre governance). With DSR remaining at 0% for an extended period of time, it would be advantageous for the sake of gas fees to change back to an implementation which doesn’t deposit to DSR.

I propose setting the cDai implementation to the CErc20Delegate which is already the implementation for cUSDT and setting the interest rate model for cDai to that of cUSDT. The interest rate model change is necessary because the current IRM takes DSR into account. The actual interest parameters (base rate, multiplier, jump multiplier, and kink) will remain the same.

The end result of this proposal will be gas savings for users. This proposal has been simulated on a network fork to ensure expected outcome and uses contracts which have already been part of the Compound ecosystem for a long time. For more information, please see this post on the Compound forums.