That said what you said in your last post is simply not true (so i do not see where i supported your argument) there is no limiting factor (apart from general weight and slot limitations) in making your KingCrab a missile or Energy Boat in the TT Battletech rules to my knowledge. (same with the Urbanmech)
And nowhere did I say that CBT customization rules preventing anything of the kind. Rather that the stated design goals of the HBS:BT system and its implementation are in existential conflict, which presents balancing concerns.
I'd be perfectly happy with a 1:1 stock environment or a full on "do whatever the hells you want if you have the time and C-Bills" environment. What is being presented right now is a very strange middle ground that tries to be both things and yet ends up being neither while also not succeeding at the stated goal of preserving an individual variant's essence.
Wait, what? As a person who came to this game via MW2 this is mind blowing to me.
What is the distinction between 'standard' mechs and Omnimechs then? Because I thought it was the Omnimechs ability to mount whatever you can cram on there.
This is a complicated answer. The short version is that the only thing a mech has to do to be a legal design in the tabletop is adhere to the tonnage and critical slot requirements. Beyond that, so long as you're in compliance with the basic construction rules you're good.
IE: A Locust cannot carry 200 tons of equipment or mount 80 clan-spec light machine guns.
Now there may be house rules that limit some customizations or require players to only use variants described in sourcebooks, but that's for individual players to hash out amongst themselves.
The primary difference between a standard mech and an omnimech is that the omnimech is specifically engineered to be re-customized on the fly. One can generally change everything (except the engine, the internal structure, the armor type and heatsink type) on an omnimech in a matter of hours. The same procedure would take weeks to months on a standard mech.