Sec. 5604 of the James M. Inhofe National Defense Authorization Act for Fiscal Year 2023 specifically addresses the issue:

"A flight instructor, registered owner, lessor, or lessee of an aircraft shall not be required to obtain a letter of deviation authority from the [FAA administrator] to allow, conduct, or receive flight training, checking and testing in an experimental aircraft if 1) the flight instructor is not providing both the training and the aircraft; 2) no person advertises or broadly offers the aircraft as available for flighty training, checking, or testing; and 3) no person receives compensation for use of the aircraft for a specific flight during which flight training, checking, or testing was received, other than expenses for owning, operating, and maintaining the aircraft."

With the president's signature, experimental aircraft owners may resume receiving instruction in their aircraft without having to jump through this frustrating hoop.