I can see your point.
And to my eyes he did struggle with pace in Liverpool game - with first steps Pool defenders and midfielders got too close to him and he could not proceed. So he has some limitations.
At the same time I feel you are not doing justice to his output. I agree with your assessment of "human pin ball" regarding Moura - no one knows to which direction will the ball bounce off from his feet. But Deki has done more than this comparison suggests. To be better than pin-ball reference, it would have been enough to help us retain the possession and maybe play some cleaver passes. But in reality Deki has been laying out assists in nice frequency. He has set up 8 goals within 1200 minutes on the field. While Moura has managed 15 across 7733 minutes. One has assist for 150 minutes on field, other 515 minutes. At that - Deki had to get used to new league, while Moura has been here for years. When he first joined, he was trusted to only play 208 minutes of football and he provided 1 assist (no goals) in his debut season.
So yea- from one hand - comparison with Moura will put Deki in good light. On the other hand, his actual output is totally from different dimention as well. So he is not just slight upgrade. It is closer to switch from playing 10 against 11 and having 11th player added to team..
I think his future lies as a #8/#10.
......Plus, even if he does eventually get usurped in the first XI; that bodes well for our bench.