ATF Improvement and Modernization Act of 2020 or the AIM Act of 2020 This bill removes certain limitations on the authority of the Bureau of Alcohol, Tobacco, Firearms and Explosives to conduct activities related to the administration of federal firearms laws. The bill removes, among other provisions, those provisions that limit the use of firearms tracing data, require National Instant Criminal Background Check System records to be destroyed within 24 hours, and prohibit the denial of a federal firearms license due to lack of business activity. In addition, the bill removes the de novo standard of judicial review for appealing the revocation or denial of a federal firearms license.