There is general problem here that we need to untangle before we can think about deploying reserves at all.
I take it we all agree that we should only be playing with excess reserves. However, the amount of excess reserves is constantly fluctuating due to the relation between inflow to the treasury and increase in circulating supply. For example, suppose you allocate 10% of excess reserves to Aave, but then bond sales drop off and excess reserves shrink. We may now find ourselves with a 20% allocation to Aave.
So at best, any allocation of excess reserves will require a good deal of active management, or settling how often we will rebalance our portfolio, so to speak.
Also, excess reserves will be determined in part by the APY for stakers, as this will largely determine the rate of circulating supply increase. So my sense is: we need to first figure out what we want for a long term sustainable APY. Only then can we make informed decisions about how to deploy the Treasury.