Tap root question

Ok, I've switched from the "pre soak" method to the "moist paper towel between two plates" method of germination. It's been 24 hours and I see that some seeds have the tap root showing. I've heard that some people like to let the tap root grow a little before planting. How long should I let the tap root get before planting? Or should I plant once the seed splits? Thanks

I plant in soil and wait for the sprout. If soaking, plant as soon as the seed splits.

you can also let them get 1/4 of an inch long but not much longer before they find their way into the paper towel and you break the root as it has ancored itself