"If savings prior to January 1, 2024 is not a deduction, then the other current deductions and Social Security will zero out anything that I may owe".
I think I understand what you mean but what you've written makes no sense, so, for the avoidance of doubt:
Savings earned prior to 31/12/2023 is exempt and not taxable.
US Social Security and UK State pension, along with most government or civil service pensions are exempt when remitted to Thailand,
You are entitled to Tax Exemptions Deductions and Allowances, known as TEDA. A person under age 65 years of age might expect TEDA of around 60k per year. A person over age 65 years is entitled to TEDA of over 350k. IN ADDITION, the first 150k of income is zero rated for tax. All of that means you can earn 500k, before being taxed (if over age 65)
The following is worth reading.