I always seem to have the problem of the plants having to wait for me to get around too it. In my earlier years, when I had more time for such things on my hands, I would always transplant them into net pots in the house and keep them there until roots came out the bottom then transplant them outside. They probably had the first set of true leaves on them by then. now I generally start them in potting soil in '6 packs' then was off the dirt and transplant when I can, leaving them outside the whole time.
Regarding what you said about plant support: I personally think the support provided by the hydroton is superior to soil for newborns. There is more give so if the plants happen to get pushed over they're less likely to snap at the soil line. When they're larger, that is another issue. Then you have to worry more about your troughs "rolling over" in heavy wind more than the plants toppling out of or pulling out the net pots. Any plant that top heavy generally gets overhead support anyhow.

Hello Devin,

Well, there is actually no specific time to move seedlings outdoors, in fact, moving seedlings outdoors will depend on the type of plant you're growing and yes even your local climate condition. With regard annuals and perennial seedlings, these can be exposed outdoors when all danger of frost has passed. Again, it will all depend on your local weather so it would be advisable to have a chart that can give you an overview of the weather in your area..For some plants like tomatoes and peppers, these crops prefer warmer conditions, so move them until daytime temperatures are consistently above 18 to 20°C. Hope that helps :)