Joyce I think a better way of looking at this proposal, and to evaluate what your asking, is to look at current stablecoin allocations for the Treasury. Current we have:
1m DAI in Aave - Aave has $14 billion TVL
330k FRAX in Convex - Convex has $8 billion TVL
You're asking for 500k DAI - Your TVL is $10 million
So yes it might only be 1.5% of Olympus' DAI but it would be a significant allocation from the treasury compared to existing positions. Also I think the "minimizing risks" is a bit of a red herring since your protocol is not battle-tested yet while Aave and Convex have a long history already (in DeFi terms obviously) - so you could argue that your protocol has a higher risk profile than Aave and Convex regardless of your asset strategies.
Again, I'm not saying I'm against depositing DAI in Gro but considering the above I think 100k DAI should be the max allocation for now until Gro is more battle-tested.