>>96546872
Without gun depression the only way you can hit stuff at a lower elevation than you is by counting on projectile drop.
However this is not exactly convenient for one, and for two the Fellblade has an accelerator autocannon (which I assume means it uses railgun tech) so the trajectory would be super flat, as represented by its 100" range, which would make this even shittier to try an pull off.
It's really stupid to have blocked that off and just adds on more stupid shit to an already impractical design.