In early escalation league rounds, players are forbidden from using advanced rules. Is that just referring to the advanced rules section of the books? (I.e. Hacking, terrain, and scenery)
yes, although some of the rules can be more... relaxed... eg. technically Hacking Devices are in the advanced rules, however remotes (Vedic Aleph and Onyx CA) use remotes for light infantry. So either the requirement for a HD is relaxed, or the limitation of not being able to take one is relaxed (but the limitation is still there for hacking programs)