How can Page be both an FBI asset and also an excuse to surveil Trump. seems like a huge conflict of interest.
The question is, did he keep these two on the hook in order to obtain more information for counterintelligence about others? In that case, he would go from someone who merely gave the FBI a heads up about two Russkies who were trying to recruit him (and certainly others) to being a full fledged asset.
Did the FBI suspect Page of being a double asset? If so, there is nothing in the Steele dossier to that effect, nor is there anything in the Papadop-got-the-ball-rolling theory that pushes that theme. There is no representation anywhere that Papadop and Page even knew each other, nor did Papadop in his drunken rant even hint that Page was the contact point for Russians who had dirt on Clinton. If FBI had such suspicions, you would think that would have been presented to the FISC. It wasn't.
To the point: it's not a conflict of interest at all. It's evidence of corruption if true. You cannot claim you need to have Title I surveillance of an asset you control, unless you suspect the asset is a double.