MechDB: INVICTUS Pretty fun, intimidating stream of missiles. Split groups between the MRM40 and the 3xMRM10s. Or chain fire for a continuous stream of death!
IMHO, if you really wanna achieve MRM60, 2xMRM30 on both sides is better because you can strip arm's armor and fit a LE and MRM10 are really heat inefficient. Also, nothing stops you to fit XL 2xMRM40, maybe downgrade engine a little and fit more JJs for poptarting (MRM40 ghost heat is really low, 2xMRM40 is manageable).
Great points, especially to improve the concept. Wanted to see what I could do with all 4 missile hardpoints. The recycle rate doesn't even make the MRM10s feel much better anyway. MRM80 sounds like a better way to go.