>>8165811Kind of,
The designer of the Bulwark complained that he felt like this guy's pusher-mech was too derivative off of/identical to his, and that he would be effectively undercutting the sales of the Bulwark files by then releasing his derivative design for free.
So since the this guy didn't want to step on the Bulwark guy's toes, he went back and further refined his mechanism using more of his own earlier designs.