I'm so glad you mentioned that this person is medical. They have had a lot of scrutiny.

Other than telehealth, the only home office work for a doctor is administrative. This is the IRS take on home office in a nutshell:

The IRS has two main home office deduction rules:

1. Regular and exclusive use. The space must be used regularly for business activities and exclusively to conduct business. As a physician, this could mean a designated space where you manage patient records, conduct telehealth sessions, or handle administrative tasks.
2. Principal place of business. Your home office must be your principal place of business or where you meet patients, clients, or customers in the normal course of your business. For doctors who split their time between a hospital, clinic, and home office, the home office must be used for substantial administrative or management activities with no other fixed location where you conduct such activities.

That is why I asked those first two questions.

I watch and use the resources from these folks. Here is a specific link for you:

https://www.whitecoatinvestor.com/tax-deductions-for-a-home-office/

For issues of double-dipping, how the expense report reimbursement affects itemizing, and why you can't use the safe harbor method, I found this:

https://wcginc.com/kb/home-office-deduction/

"According to IRS Revenue Procedure 2013-13 which reads in part-

.02 Reimbursement or other expense allowance arrangement. The safe harbor method provided by this revenue procedure does not apply to an employee with a home office if the employee receives advances, allowances, or reimbursements for expenses related to the qualified business use of the employee’s home under a reimbursement or other expense allowance arrangement (as defined in § 1.62-2) with his or her employer."