An apparatus includes a housing, a platform, a buttress assembly, at least one retainer member, and an indicator. A portion of the platform is exposed in a gap defined by the housing. The buttress assembly is exposed in the gap defined by the housing. The retainer member is configured to selectively retain the buttress assembly against the platform. The retainer member is further configured to release the buttress assembly from the platform in response to a clamping action of an end effector positioned in the gap defined by the housing. The indicator is configured to provide indication of a state of one or both of the buttress assembly or the at least one retainer member. The indicator is further configured to change state in response to a change of state of one or both of the buttress assembly or the at least one retainer member.
