Can anyone tell me how I'd make use of all the 3 layers hairs can have when making .swf hairs using the vanilla modding .fla?
There are much more than the 3 layers of a PNG static hair mod (4 static hair, 4 dynamic hair, 4 hair costume, plus the accessories...)
They're all listed in
How to arrange layers in your hair mod (from top to bottom).
All the hair and hair costume templates have a head reference and are aligned, so when you copy a shape from a template to another and "paste in place", it will be a the good postion and you can align things easily.
You can use as many layers as you want inside a template:
I usually have "line", "shade", "highlight" and "fill", and I duplicate the "line" to change the lines to fills (so the lines don't flicker when zooming in and out) and change the "line" layer made of actual lines into a guide.
You can even have several templates of the same kind, like two DYNAMIC_HAIR_TOP if you need to have two separate stands on this SDT layer. The first registered in the settings will be the one under the others.
You don't have to mind about the registering order of other templates, they're arranged by the game, not in the mod settings.
For this hat, it would be better to use the separate "headwear" template that already a front and back layers (they are actually symbols, you have to draw inside them for them to work properly).
These are placed just under the HAIR_COSTUME_OVER and the HAIR_COSTUME_BACK templates.
This is a bit complicated to explain, because the terms "template" and "layer" are used for different things...
When I used "template" above, it is to designate the main symbols of konashion's SDTMod.fla (that we also use to call a "template"), like "Headwear Template" or "Dynamic Hair Template" that are in his "Templates" folder.
When I use "layer" it is to designate Animate's layer (or I said "SDT layer" instead for the game hair layers).
Do I need the template extensions version?
If you mean loader templates (like sby's), I guess not, because they don't have more templates for the hair, hair costume or accessories as far as I know.
I may be wrong, as I barely used those templates, but any hair or head accessory can be made with konashion's template (with the exception of advanced physics mods that require stuntcock's
Dynamic Hair Extender).
I hope I answered you question, don't hesitate if you need more help.
It's a bit tricky to give indepth advice as many things are usually discovered after hours of trial and error...