Source:
https://twitter.com/RiotMAXtheX/status/1096063520263847942
https://twitter.com/RiotMAXtheX/status/1096078260893597697
They have also agreed to not use the early waveblock-exploit as shown by 100T in the LCS.
Source:
https://twitter.com/RiotMAXtheX/status/1096058663377227777
EDIT: People keep asking about the minion block thing:
https://www.youtube.com/watch?v=gIfthhIjvIo
Thats 1 of the examples. Theres others aswell, that are also "not allowed" aswell.
100T DID talk with riot about this specific one however and got an OK so they did not fuck someone over. It was a communication issue from Riots side last week.