It's a little unclear but when Madara was first summoned into the war that was the first time he has been alive since his death, so the time Kabuto first summoned him to intimidate Tobi he was unconscious or maybe it was just his corpse. But when Muu used summoning jitsu (not Edo tensi) he was conscious for the first time but it wasn't Edo tensi nor did Kabuto used Edo tensi before that because Madara doesn't remember that moment. It's possible that Madara was unconscious when Kabuto infused him with Hashi cells but it doesn't add up for me. (Spoiler) The reason that Madara was Kabuto biggest trump card is because he keep in secret who ressurected Madara so even if he was some how forced to release Edo Tensi Madara wouldn't be release. He also wouldn't need to control Madara because he has the most likely has the same objectives as Tobi and himself. Feel free to add anything I missed because I feel like I did.