"It's like Robotech plus Gundam, only not."
Barely anyone I've spoken to has even heard of this system, which is a shame. People may be more familiar with Talsorian Games' other flagship product, Cyberpunk 2020, but in my opinion it's Mekton, the game of supposed strategy and giant robots, that wins.
It's well known you can never have too much Dakka, and even though MZ+ allows you to get a lot of firepower from a single weapon, I don't feel that there are enough options to create "any" weapon. For starters, I can think of a number of iconic weapons from sci-fi the system would require the "Special Mekton Trick" generic upgrade to handle, which can be severely undercosted for what it can offer. For example, Tesla Coils would clearly be an Energy weapon, but there's no Shock upgrade for Energy weapons. Likewise, what if you want a laser that sweeps from side to side rather than "lol Itano Circus?"
So here are a few semi-tested upgrades, and then later there will be some highly experimental ones which may well be utterly broken. Remember, all weapon upgrades can be "stacked," so you can certainly have an Arcing Area Infinite Burst weapon, but yes you do have to resolve every single one of those individual lightning bolts individually.