There probably won't be any noticeable signs of progress because a lot of the players at his disposal are not good enough for United, his system, and some, the PL. Until they have had a chance to address the fact we don't have a striker, we have crocked defenders, a hologram for a goalkeeper, and a midfield with no legs, he isn't going to be judged too harshly on performances or even our finishing position. We were firmly on this path to shitness with Ten Hag at the helm, nothing has changed except he's asking them to play a new system and they could barely play the old system, this is what you get.
They don't have a choice but to support him at this point. Promise or not, this team isn't good enough and sacking him and brining in another promising manager will go exactly the same way unless this team is ripped up and they start again. I said at the time when we were signing players Ten Hag wanted for his system that didn't work in the PL that we would be set back years by the piss poor recruitment. Mount, Onana, Antony, Hojlund, etc, these players aren't good enough for any system and now we're paying for it. Forget who the manager is, we could air drop Big Sam into the mix, go counter attacking and still lose games with these players, they're a total bunch of misfits.
Like I said before, as much as people want him to be sacked if this continues, it just isn't going to happen. The CEO hand picked him and the board have given him nothing but verbal backing, even when he's said this is the worst United team ever. In the summer, regardless of what happens this season, they will throw a couple of hundred million behind him and start asking for results. The current situation for any manager at Manchester United is impossible due to decisions made before their arrival.