The Avionics versus Stability and Control training debate is certainly an interesting one.
In my view it is very important to teach avionics testing as thoroughly as possible because, as has been said, there is so much avionics testing done.
But, and it is a big but, on a young or development aircraft it is quite easy to trip over a stability and control issue when you least expect it (say doing ‘avionic’ stuff) especially with FBW. If that happens you can lose the aeroplane if the pilot is inexperienced/poorly educated in stability and control issues.