av2map20.wad is a remake of the starting area from AV.wad MAP20, built only using my memory, after not having played that map in a couple years. The remake pokes fun at how two of the player starts are placed behind impassible lines, trapping those players at the start. So, maybe you can think of the remake as a special mission for the trapped players.
av3map20.wad is an incomplete remake of the rest of AV.wad MAP20, built only using my memory. The last time I played that map was when I recorded a speedrun of it, so I had trouble remembering all of the rooms and how they connect to each other. I decided to give up before building everything I remembered, since I would just run into a mental dead-end. There is no gameplay in this remake, just rooms.
id Software - Authors of the programs I use - Kim Malde, Mattias Berggren and Vincent Catalaa for MAP20 in AV.wad - Creaphis for the mapping from memory idea -