HOME OFFICE DEDUCTION Using Retail sq ft

I read an article/post on how LLCs use retail square footage price per sq ft times their home office sq footage to determine a monthly “rent” comparable to leasing office space outside of your home.

My CPA estimation had about $6k deduction for the year on my home office. The other way would compute to $1853.58/month and $22,243 annually(using $13/sq ft retail averages x 142.58 office sq ft). This article also states you may have a monthly rent deduction for the use of a garage (say $100/month).

Has anyone used this method before? If not, do you think it is a big red flag since home office deductions are usually the biggest flag for LLCs.
As you can see from my number above, the tax savings are over $16k!! :shocked

Good luck getting the IRS to agree. Does this article quote a PLR or tax case?

If your LLC has a large rental expense, then you have a large rental income to report on your own 1040. Seems like a wash no matter how large or small your “rent” is