You still have time to impress them or piss them off

If you have had done it natually in the very 1st thank-you note, that'd be perfectly OK to everybody.

However, sending another lengthy email to "impress" somebody, in my personal opinion, is not quite thoughtful. It might be annoying, especially on Friday. My reaction would be: c'mon, gi'me a break, it's weekend.

Therefore, I think it is a bit risky, unless your interviewers are extremely nice people, or you are good looking.