We are PembRock Labs team.
We ask Ref.Finance for supporting our REF lend pool with by REF tokens.
Utilization in REF pools is almost 100%
Sorry if I’m not familiar with how exactly your protocol works, couldn’t find source code on GitHub. But, can’t you just raise borrowing rate? If it’s too cheap then any $REF deposited would be instantly used for more leverage, which doesn’t help lenders who are locked into their position