I'm unsure I get the idea. Basic turrets are a super cheap tech, why we would need the sentry guns? I mean no disrespect though, I like the idea of a specialized sentry gun...
Turrets require research, and in some mods like Py they can be hours away due to that. This mod is intended for mods where researching turrets is not immediately possible, or where ammunition for ordinary turrets is prohibitively expensive early on.