I've linked this before but the entire series is great reading for anyone interested in this sort of thing, even from a historical perspective, tho it is crossed with contemporary analogs where possible.
The Dubious Quick Kill, part 1
When I have done EW sparring, nothing was off limits - the head is just like any other appendage and the general rules apply - slash the appendages and stab the trunk. However in most legal cases one is on the defensive side and unarmed vs this kind of attack. I was taught to use basic escalation means from redirect and evade to redirect and counter, armed or not - all successful redirections contain within them an opening to escalate if escape is not an option.
Either way, mobility is paramount, and basic boxing and circular foot-work is so important it cannot be overstated. This is how you create space and doubt in an attacker (they are not opponents!).
If you are confronting a single aggressive individual you are either in the ring, in a situation you could walk away from, or at a very raucous social occasion (where you could disengage with loss of pride). If the lesson does not include this as a given or strong possibility it is of dubious value. Bad guys don't hunt solo unless you are a really soft target, and they (as you should) will use any improvised or carried weapons at their disposal. Lessons should walk back from situational awareness to evasion to physical counter. Pepper spray should feature prominently as an escape tool.