One of the bigger mods, I think it was Battletech Enhanced 30XX or something like that did have the ability to upgrade or unlock moe deployable mechs. How ever, when i was looking into it, it does not function properly with the latest update/dlc. I dont know if the modder is working on fixing that or not, but I too would enjoy being able to field more than one lance. I do know a lot of others argue against allowing more more, given the Leopard was supposed to only be able to hold Four Mechs, no matter what the weight they ended up being. In the lore it was not about the weight of hte mech so much as to the sorage rack or cradle that held the mech in place was the limitation. Unions (and I may be wrong, this old OLD memory stuff) held up to Twelve mechs and Overlords were cpable of carrying Twenty Four. And thats just the Mech alone, not counting the Aero Space Fighters each was supposed to be able to transport as well.