AC_DC

Quick question for the experts here. If the 80% lower already has the rear take down area milled for the rear lug, is it alright to just mill the fire control pocket? Will there be any functionality issues? For reference, I've read this can be done with AR-15 builds (https://www.ar15.com/archive/topic.html?b=3&f=4&t=675681), but I'm not sure if this is also true for 308 builds. Thanks!