Lomonosov Endgame Tablebase says it includes all endgames with 7 pieces. But does that include things like KQQ v KQQQ? At every possible position?
Such things seem highly unlikely, but theoretically possible. I recently watched a Fischer-Petrosion game that went to 4 queens in the endgame that also included a bishop v knight and some pawns. They eventually agreed to a draw.
Other unlikely things: KBBvKNNN, KQRvKQQ, KRvKBBBB. Have any of these been evaluated?
So I guess the general question would be, have all 7-or-less endgames been evaluated where at least one side has 2+ queens, 3+ rooks, 3+ bishops, or 3+ knights?