You will have to redo your squad logfiles if you have some prepared in order to gain advantage of the new features. One of the useful one (thanks to Theorist) is the CTRL-G toggle which allows you to see under a ship, facilitating collision placement.
Is this required to play? Do I have to remake all squads in order to properly use the new firing arcs, etc. Or do I just lose some of the new features? Specifically, will I be violating any of the rules for Theorist's latest HiLo vassal tourney if I use squads made with the old module?