Taxi consupmtion CFM 12 kg/min. APU 2 kg/min. Minimum warm up 3 mins. to save 200 kg you need 200/(12-2)+3 = 23 minutes taxi time. To break even need to consider increased fuel burn on each and every sector due weight and maintenance cost.
It may be viable, but "up to 200 kgs" is marketing communication. True, tug cost and flexibility will play a substantial role. For CJ even maybe tug non-availability.
FD (the un-real)