yes, plant as soon as you see a taproot if they are in standing water. there is only so much water a seedling can absorb before it rots. if you have had success in the past with this method it could have been a particularly resiliant strain, but i wouldn't count on it for continued success. the water at this stage is only to soften the shell and make sure it cracks and nothing else. this is why people use paper towels, to create an environment close to warm soil while also having the ability to view the seed as it progresses. once the shell is cracked and throw it right into the dirt and keep moist (not soaked) and warm. some people keep it in the dark till it breaks soil, some don't. the important thing is to make sure it's warm and that the soil has enough moisture for the root to be able to feed.
this is how i germ my seeds and i have nearly flawless results, i would say at least 98% success.
1. fill 16 oz party cup with lukewarm water
2. put 3 drops of superthrive in the water and mix well. (the superthrive is optional. it's a bit pricy and some people call it snake oil but i cannot deny my results since using it)
3. soak seeds for an hour or so in the cup (i like to swirl them around and see how they "behave". some sink and some don't, but i usually get them all to germ. swirling is for amusement purposes only at this point)
4. get 1 full sheet of paper towel, fold it in 4ths, and dip halfway into cup, fold dry half onto wet half and squeeze gently so whole paper towel is uniformly wet. it should be wet but no so wet that you could swing it at someone and get water on them. only excess water gets squeezed.
5. put seeds (several if you want) in paper towel and fold over. it doesnt matter how you fold it just make sure you have at least 2 layers on each side so it doesnt dry out.
6. (i think this step and the next one are the main reasons for my success.) place paper towel in ziplock bag and fold over but DO NOT SEAL. you want it to breathe a bit.
7. take ziplock bag and stick it on top of your cable box or computer tower or something else that is extremely warm all the time.
now just check on them a couple times a day. the bag will get a lot of condensation which keeps the paper towel moist, but this also means you have to check every so often to make sure there is no mold or mildew (i have never once had mold or anything happen but i'm sure it could). flip them once a day. i have germed at least 10 strains this way and have similar success with all. you should have taproot within 2 days, maybe 3 (it has never taken me longer than 2).