You are posting old law. The law was changed. PPP forgiven loans and EIDL Grants are 100% non-taxable. You can deduct the expenses for which funds were used.
From the analysis you linked:3. COVID-19-related grants to businesses do not qualify as tax-free under the general welfare exclusion and are generally taxable, ...
That is incorrect. Some grants ARE taxable to the business. It would be quite helpful if someone would answer the OP's question ( not a PPP or EIDL Grant)