Oozleanswered grow question 2y ago I've taken plants about that size from 1 gallon soil and thrown them in DWC, so as others have said, coco will be fine. I changed the res once or twice during the first week though because I started to get a lot of foam in my res.
It took about a week to get the roots through the net cup. I lowered the light intensity and set the EC at .8-.9 until the roots hit water and she was drinking a good amount.
Getting your water level might be tricky, so using a spray bottle to spray the middle or bottom of the net cup will help. You could top water too, but it is better to water from below so the roots search for water down and not up.
Adding a mycorrhizae product should help it transition easier, but not really needed and if you are using h2o2 I think it will just kill the beneficial's in a root inoculant.