Your comments

Thank you very much.
You're right.
I've been testing and other programs behave the same way.

Therefore, this is not a bug, but the problem persists, and could be seen a small improvement, even for the standard behavior of iOS text controls.

Or the finger is already in motion when it contacts with the surface, or the keyboard is displayed.

It would be nice to have a greater margin of tolerance before opening the keyboard. If pressed but there is no significant displacement, the keyboard is not displayed until at least 1/4 second.

Obviously not a critical problem, but it is slightly annoying.
On the other hand, taking this opportunity, congratulations on your work.
Hi Alexander. The file extension is 'js', and the standard JavaScript words works well, but the specifics of Unity looks not highlighted.
Very important for me. I just buy the app and can't open my files.