Hey dude. I'm definitely no expert, but no, you don't need to see runoff in the seedling stage and localized watering is better then total saturation of the soil, especially with the size of pot you're using. There is no root system to uptake that water and saturation will suffocate them. Also, the larger the pot you start your seedling in, the more medium you have to disperse any moisture. Overwatering too soon can be a big problem in a bigger pot and can take a long time for it too dry out. I usually look to start getting my 10-20% runoff at week 3-4 when there's a root system to take it. Play this by ear as this will be specific to your plants growth and growth rate. At this stage, even when I'm looking for runoff, I know the root system isn't throughout the entire medium so I localize the watering about 1-2 inches from stem (making like a little mote). Finally, always make sure to let the medium dry somewhat or almost completely (in Vegetation) b/t every feeding. There are cheap little gauges/probes kicking around that do read soil moisture level, but the good ol' finger in the soil works too.
Hope this helped! All these answers came from personal screw up's, LOL!
