WER Issue on a PPTQ
Effectively, 3 rounds of Swiss for 8 people is very similar to single-elimination; the 4 people who lose in round one can continue to be paired, and play if they want, but they can't win the event.
The important thing is that you observe the MTR rules re: single-elimination matches - i.e., no draws. (MTR 2.5, end of match procedure, and the paragraph about single-elimination.)
d:^D