Cheer? No. Clapping and showing respect for the other Team? Yes.
There is no need to Boo at anyone. How would you feel EU woudl do the same when the finals are held in EU and Loud would get Boo'd at?
You would find it disrespectful. c:
Home crowds are gonna be biased no matter where, yea they should be respectful, we saw that in Istanbul too, they werent exactly respectful to loud or optic or any othee american or some asian teams