1 min initial agitation then 10 sec in every minute 11.30 has worked well ...
Recipes & dev times using Developer Kodak XTOL
Ilford Delta 400 at 800 in Kodak XTOL STOCK
10 minutes at 20°C/68.0°F
Ilford Delta 400 in Kodak XTOL 1+1
11 minutes, 30 seconds at 20°C/68.0°F
Ilford Delta 400 in Kodak XTOL 1+1
11 minutes, 30 seconds at 22°C/71.6°F
Ilford Delta 400 in Kodak XTOL 1:1
11 minutes, 30 seconds at 20°C/68.0°F