No, I don't want to pay extra for cross-training specialist.
Over 55% in the poll say they would use cross-training always if it was optional. What's the point of creating a new feature for the minority of people who don't like it?
Perhaps the scenario like this will keep everyone happy....
Trainer Type:1. Career Extension - Cross-Training
2. Career Extension - Normal-Training
3. Fitness - Cross-Training
4. Fitness - Normal-Training
5. None - Cross-Training
6. None - Normal-Training