Per IRS Publication 529 at https://www.irs.gov/pub/irs-prior/p529--2019.pdf you can no longer claim W-2 job related expenses unless you fall into one of the following categories of employment, or have certain qualified educator expenses.
•Armed Forces reservists.
•Qualified performing artists.
•Fee-basis state or local government officials.
•Employees with impairment-related work expenses.
So if your membership/employment/participation in the TXSG is not considered to be serving as a reservist, you can't claim those expenses. Now personally, I would expect you to qualify as a reservist if the TXSG is subject to being called to active military duty by the federal government. But I don't know that for a fact. You may want to ask your commanding officer if you are eligible to be called into federal active military duty. If so, then you qualify.
