I am not owning Caliban and only seen him in some missions but what I have seen his abilities are lacking and the synergy is small or barely exists. The theme is interesting but most players whom I meet saying he is another one frame that came dead on arrival because the abilities are weak.
I do not really making orders because I can accept he needs some work, like Inaros, Chroma, Frost (tweaks mostly), Hydroid, maybe Ember again, and frames like Loki which could be good in different situations but he is old and barely updated.
I personally would agree with the full look at all frames and see if every ability can be useful or not but that takes time from them and they barely want to touch up the old content so my hopes are low on this matter.