I, finally, was able to sort my issue out with BIR yesterday. It looks like I skipped one step before proceeding to pay for my certificate fee together with the documentary stamp.
When I got to the office of the Administrative Assistant, my request was accommodated right away except that there was a confusion as to what document we were trying to work on. It seemed that if I did not pay my income tax on time I would not have made it yesterday.
Taxpayers with a request for a Certified True Copy of their ITRs for years 2014-2017, for instance, are most likely unable to get results in a day as it takes time to verify all entries via the database.
It is highly recommended then that the said copy be acquired right after paying for the annual ITR.
Another thing that I noted is that elements in leadership boards in BIR tend to fluctuate rapidly so the best move is to address the letter to the Administrative Assistant in general. Yesterday, I discovered that the office has many people working under that title and that the lady who received my letter of requrest was actually the Officer-in-Charge Chief of the Collection Section and assumes the title of Adminstrative Assistant, too.
In summary, a Certificate of Foreign Inward Remittance may invalidate a freelancer's self-employed status as taxpayers can actually become self-employed individuals. Those who pay for their taxes may have the right to apply for a housing loan. Tax-exempt people who are capable of making such a loan are those who receive hard currency straight into their bank accounts.