Insignias

question: do ele insignia armor stats stack? like aero +10 and the elemental +10 equal +20 for lightning???

Yes, you get the general +10 vs elemental, and if the damage is lightning, then you get an additional +10 protection

I'm assuming you mean the two bonuses from insignia, which state a bonus vs all elements, and a bonus to a specific element.

Yes, those stack for that armor piece only.

As posted about they are not Accumulative but rather "applicable" to be Applied in Abundance to your Armor. One piece at a time.

The do not stack 5 times cause you have 5 pieces of armor on but stack within themselves.

To clarify:

The insignia bonuses will stack, so you will get +10 to all elements and +20 to lightning.

However, the insignia will only work against hits that hit the body part covered by that armor part.