Create 2 single-fund portfolios in Endowus to simulate a multi-fund portfolio?

As title states, can I / should I do this to save on the 0.1% p.a. flat fee? I’m thinking of investing my CPF OA and the additional $2 transaction fee to agent bank definitely makes up for it for any investment value above $2k ($2 / 0.1%).

Am I missing anything here? First time dealing with Endowus and investing of CPF-OA funds.