Surely the argument for the Sukhoi SU-35S is less than that for a Eurocanard with thrust vectoring and updated avionics.
If/when the F35 is cancelled or fails to deliver we would be forced to cat and trap our carrier. Folding wing updated Typhoons would be nice but would involve the MoD and BAe. Which makes Rafael or Superhornet a better option. But would we buy a major off the shelf French weapon system?
The F18 was first introduced in 1983. Although it has evolved it is still largely a 30 year old platform. The SU-27 is a similar age. Typhoon is a full two decades more modern.