I think that the word “reasonable” is reasonable. I agree with that point. It is not unheard of that someone would argue, “You can't send me to this country because I'm not going to get tried within a reasonable time.” We would go back to the country and ask, “Do you have laws about ensuring that somebody is tried within a reasonable time?” For example, the United States has speedy trial laws, and we refer to this pretty regularly when people raise concerns about that.
I think it would be unduly restrictive to insist upon a particular time period, because there are so many things that you cannot predict about how a trial is going to unfold.