I had read about that as well. My heartburn with it is, it would be considered fruit from the poisoned tree. Since the warrant is essentially illegal due to it being based upon false information, anything discovered due to its execution would be illegal.
That’s the point of FISA. It makes legal what would normally be improper. The whole reason for the conspirators to allege Russia and to involve UK and Australia was to place domestic surveillance for political purposes under FISA and make it appear legal.
The determination by the USSC that Mueller’s and other convictions were ‘poisonous fruit’ is not that important because it’s far in the future when the goal is to cripple Pres. Trump and those close to him right now.