If those steps are not taken, some errors might appear in the remote engine's karaf log, in addition to the fact that flows won't be running successfully on the remote engine:
Warning! If your proxy password or/and proxyLogin contains special characters, it will need to be encoded. So in the case of proxyPassword = 13!)4543G, using www.urlencoder.org (for example) produces 13%21%294543G%0D%0A.