Yes. Generators are not required to keep copies of manifests and biennial reports on site. Generators may keep copies at a corporate headquarters. However, the generator must be able to provide to EPA information on, or access to, these records.
Although CESQGs are not subject to recordkeeping, including notification, biennial reporting, and manifest requirements, they are still subject to limited generator waste management standards. 40 CFR 261.5 sets forth the special requirements for hazardous waste generated by the conditionally exempt small quantity generators. However, some states may require recordkeeping or collect data on CESQGs through inspections, so you should contact your state environmental agency for guidance on CESQG recordkeeping requirements.