Maximum Open Order Limits

The exchange limits the maximum number of open orders allowed on a BOE port to 100,000 per port (BYX/EDGA) and 300,000 per port (BZX/EDGX). New orders will be rejected once this limit is breached until the number of open orders drops back below the limit.

Cboe Titanium U.S. Equities BOEv3 Specification - Maximum Open Order Limits | Cboe