The Mauler is so tall and those missile hard points are really high. This allows for the MRMs to be launched over hills, buildings, team mates, etc. I'm actually running this on an MX90 and it works well. But I see the 2P has all the same quirks plus UAC jam chance -20%. So I am posting it as a 2P.
After using my cyclops with 2xMRM20 and 4xSRM6+A, I can safely say that the 20s are much better than they let on from their weight! Very cool, relatively low spread and cooldown compared to the 30 and 40. Looks like a very powerful build!
I could try for once to use something like this one: using MRMs on higher tiers is more than often counter productive and I honestly dislike the idea of not using those juicy and unique 6 energy hard points (they are whispering "We are THE meta, use us!"), but those missile quirks on MRMs could be very interesting... I'll try out this build and then try my fine tuning. Only one thing about your build: the ammo will be consumed in a order like head->torso->arms->legs Since head will always be the first and legs the last, you should consider moving the ammo from your CT to the arm: it is fully armored and can withstand a punishment. IMHO with the current meta it is better to lose some ammo right from the start by losing a side torso (and you will still have plenty of ammo in the legs) than to die for a lucky alfa strike in the center or get wrecked critted by a lucky myst lynx