Even so, that feels/reads to me more like it was a 'custom design' produced in the factory rather than a customized Mech variant. The sort of gross designs like that tend to be explicitly mentioned as one-offs and generally owned by important or otherwise noteworthy people, so it's more like choosing your own set of hardpoints from the start rather than altering the hardpoints of an existing chassis. I'm sure there's at least one example that proves me wrong out there, but I think stuff like that should be very much exceptions to the rule that a 'Mech is more or less static in its general configuration...you could, with enough time and money, modify a chassis to spec, but it'd end up cheaper in the end to just buy a stock chassis closer to you end design and modify that.