All the terminals (1,2,3)are connected airside by walkway.

I usually hang out airside, either in a paid lounge or transit hotel bed (min 6hr).

When the LCC check in opens I pass entry immigration, check in and then exit immigration. The transit counter will not issue boarding pass for "non-interlined" flights to LCC when I do not have an arriving boating pass from the same airline. So carry on only will not help.