I have added the slash at the end of the public_html/blog/ and now the process takes less time, yes.
I initiated the blog sync at 11:44:02 and it finished at 11:45:30, which is much less time than before.
Now the process shows it will do up to 48 operations which is much less than the 479 it used to do before. And these 48 operations takes less than 2 minutes.
I have checked the upload process two times and the results and time to upload are almost the same. But the number of operations remains in 48, which I guess may increase based on the new contents or changes I commit to my blog.
The files-remote.json now seems not to be broken. It looks fine. So I guess the slash at the end of the physical location is a good solution this time.
The tip below the field looks fine but it does not warn about leaving the field without the slash. So I guess I didn’t follow the proper instructions when setting my server up. Maybe a warning on the screen may help?