This is exactly what I have done with immigration, and exactly what I will do in relation to this tax policy.
I do not want to have ANY contact with ANY Thai government employees, and I am prepared to pay for the privilege.
The agents can deal with them, at their quoted price. If anything comes back to me, I'll hand it on the agent and tell them to take care of it.
Of course I will check their work, but if I have the various documents for immigration and the TRD, I consider the job done for the year.