High temp wire enamel insulation
Have to say most of the reasons against the use of hi-temp insulated wire sounded hollow to me:
1) the class (or heat resistance) of the wire enamel coating does not influence solderability except perhaps you might need to use Hi-temp solder also.
2) Obtaining the desired wire & hi-temp coating might take a little extra time, so what, we are in a planned manufacturing environment surely?
3) What's the problem with Glue, use your standard mix which is not stated to be a component of "the problem".
If it's necessary to increase the bake time so what, durability & quality usually carry some price & you have a speaker with a somewhat higher rating.