Fully supported and I believe he should keep him on the bench more atleast he would know that he needs to adjust his gameplay to suit the situation of the team, if am not mistaken the number of times Manchester united have fell short of supposed victory that would have gotten and then later drew or lost the is more of the fault of Onana and just countless errors in his goal post.
I also quite agree with what you said because from every fact that has been seen by everyone and all Manchester United fans is because of Onana's fatal mistake himself. I am quite sure that if only Onana did not make a mistake like that yesterday, clearly Manchester United could have won even though they only won by one goal. But all that was lost for Manchester United so they had to fight with the same aggregate in the second leg even though the second leg will take place at Manchester United's headquarters.