It’s almost always worth SETO unless you’re constrained by engine warm up time, and as previous posters have pointed out if you practice it it’s not difficult.
Even if you only save 50kg, 50kg saved on a sector is 100kg on two sectors. If you’re a medium size airline multiply that by 200 “there and backs” a day is 20000kg a day, multiplied by 365 is 7,300,000 kg saved per year. That roughly equates to $7.3 million in reduced fuel costs per year and 65700 fewer tonnes of CO2 in the atmosphere.
On an individual level any fuel saved on taxi out remains available for use later in the sector. That extra 200kg fuel saved might just be the difference between holding longer or making a second approach and getting in rather than diverting from destination.
Marginal gains make a big difference when multiplied.
I often start the second engine almost immediately after commencing taxi if it’s a short taxi. That reduces eng 1 run time as you’re moving during eng 2 start (assuming no atc delay prior to departure) and saves a small amount of fuel. Over a career that will be a very large amount of fuel saved.
LD