IMO, the problem is they are CHOOSING when the BEST option is to let the ATHLETE select it. Like many of the other Plan Builder suggestions we have made, setting at least the default SS vs Z2 workout applied to a calendar should be set by the user in the PB process.
As of now, they have to flip a coin and it will be wrong for enough people to be an issue no matter which they choose. So fixing that PB selection option would be my priority vs flipping the switch to the other direction.