i have a recoomendation for you and your new seedling. once it pops up get the seedling into it is perminate growing pot as soon as possible. your seedling is going send out its tap root. the tap root is the plants first anchor root and if it just curled up under your cube it is the first part of stress in ts bery early life. we all know stress is bad for your plant.
studies have shown that if that tap root is allowed to curl up under neather it is more likely you will have a male plant. so the sooner you can get it into its home the better off you will be. the better off the plant will be. so take a few minutes once you see the seed pop get it to it home right away,
i grow in rockwool using 3 inch net pots filled with aquarium or pea gravel. i soak my cudes in a 25% solution of ces nutes( it has a ph buffer in it to bring my water to 6.5) rockwool has a ph over 8 so soaking it bring the ph down to the recommended 6.5.) i will get the pots ready adding my gravel and cube then fill in around the cube making sure it is strudy and ready to go. i then put the seed in the cube and cover with a dome.
this way if i have a good seed and it pops then it in its perminate home and all i have to do is move it into my system. i never have to touch any part of the seedling again.