It depends on if your "Accounting Firm" is registered with the government.  See the 15th page of the PDF (page #9) of the full BOI booklet.

https://www.fincen.gov/sites/default/files/shared/BOI_Small_Compliance_Guide_FINAL_Sept_508C.pdf#pag...

Once you've identified the Beneficial Owners, I would think this entire process take less than five minutes.  I'm puzzled why everybody is so stressed about it.

Even if an entity falls under an exempt category, I don't see any harm in filing it anyways.