General Discussion

If I understand it correctly, what I’m reading. I am definitely no expert.

I don’t think they would pay attention to a private citizen, but as trump is an elected official he should follow the federal guidelines out of respect.
I also don’t think a governor of a state has the right to go against the president, declaring the mast. Like Abbot is doing

“The flag should fly at half-staff for 30 days at all federal buildings, grounds, and naval
vessels throughout the United States and its territories and possessions after the death
of the president or a former president. It is to fly 10 days at half-staff after the death of
the vice president, the chief justice or a retired chief justice of the United States
Supreme Court, or the speaker of the House of Representatives. For an associate
justice of the Supreme Court, a member of the Cabinet, a former vice president, the
president pro tempore of the Senate, the majority leader of the Senate, the minority
leader of the Senate, the majority leader of the House of Representatives, or the
minority leader of the House of Representatives the flag is to be displayed at half-staff
from the day of death until interment.

https://www.va.gov/opa/publications/celebrate/halfstaff.pdf