I like Lancer. I also think that Lancer is missing a couple things that are important to my own Mecha Fantasy. One of those things is "a modular framework for campaign play": it works "just fine" if you have a linear adventure, and there are some great ones out there, but!

I'm not going to go into detail about my feelings on how too many RPGs just kind of handwave "do your magic DM juice, DM, you're the wizard, you can do it!" for adventure design, please take it as read that I believe "there's need for more linear design support too, we need good stuff" as well.