I have many dozens of frames next door and I am into woodworking myself. The frames are definitely planned ando/or sanded. I also lived until a couple of years

I have many dozens of frames next door and I am into woodworking myself. The frames are definitely planned ando/or sanded. I also lived until a couple of years amongst a large community of beekeepers and never met anyone that harvested propolis systematically. I am sure others do as it is a vaulable product but I suspect that most just process the hives for honey.