Graph QL query discrepancy

I want to get available liquidity from compound subgraphs. However when I query for (baseReserveBalanceUsd, totalBaseBorrowUsd, totalBaseSupplyUsd), I have to add the reserve balance to the difference in Supply and Borrow, to get to the available liquidity.

Is reserve balance a part of available liquidity on compound, so we can borrow from it as well?? Even though it isnt for borrowing on other protocols?

Yes, reserves are available to be borrowed.