WAT without disable HTTP compression

Compressed data isn't readable, so you'd definitely have to decompress it. But for a STREAM profile in the HTTP_RESPONSE event, you only need to disable server side compression - between the BIG-IP and backend server. Client side compression is still very much a possibility, though it must be controlled and terminated at the proxy. In other words, HTTP compression would be between the clients and the client side of the BIG-IP. Server side HTTP would not be compressed.