What were your FT3, FT4 and TSH on 100 mcg? How long after starting 100 mcg was that test?
How long after cutting back to 75 mcg were the results you posted?
Any changes in meds brand? Diet? Other meds? Supplements? Anything, even if it sounds insignificant?
Did you take your meds before the test, or after?
Have you changed what you eat for breakfast, or the timing of when you take the meds?
Both FT3 and FT4 are well above range and have been for quite a while. Do you have hyper symptoms? It would appear from your numbers that you don't need to be on meds.
"TSH w/reflex to FT4" is a direction to the lab. It means: Test TSH. If it's in range, go no further. If it's out of range, test FT4.
"TSH, 3rd Generation" is just the name of the test.