No I think the high temps will be good.
And for further clarification:
Mezcal is spirit derived from any agave. Tequila is derived specifically from the blue agave (along with many other regulations).
In either case the 'pinas' of the plants, once mature, are collected and cooked. They are then shredded and pressed and the juice that is collected is fermented and distilled. It is this same juice that is dehydrated into the nectar that we purchase at the store. I think what happens though is a lot of the more volatile and aromatic compounds in the agave juice are evaporated during the dehydration process, hence a lot of the flavor and aroma that would normally be in the juice is absent in the nectar.
I have been unable to find much information about the specifics of the distilling process. For example, I don't know if the heads/tails are recycled, or if the dunder gets reused in any way. I have heard that the spirit is typically rested for at least 3 months, even when left clear, but I do not know for sure.
I participated some in the onion tequila trials. Let me tell you that it is the worst spirit, probably the worst food product of any sort, that I have ever made or tasted in my entire life. Completely horrible. It tastes like you allowed a whole bunch of onions to rot along with other garbage in your dumpster, you then took all of the flavors and smells from the dumpster and concentrated them to such a degree that they would all fit into a 750 ml bottle. Ok, maybe not that bad but still bad.
I would stick to the agave nectar.
It's better to learn from other people's mistakes than your own.