The question:
Anyone can notice that any position that shows 1/2t it's close to the real 1/2. But what position is the true 1/2 Strum time?
And my suggestion is:
Show when the time is exaclty 1/2,1/4,1/8... and a button to set the time to the exact fractions like in guitar pro 7 (described bellow)
The struming feature in guitar pro 7 has buttons (red circled) to set the exact position for 1/8, 1/16, 1/32. So when the 1/8 button is clicked, the position sets exaclty to 1/8. (Like in the image below).