Putting a freshly germed seed into soil as hot as HF x OF is pretty much signing it's death warrant, stunting it at the least. I think what you're referring to are peat pucks, and I always use them. I get 95 - 100% germ and sprout with them as long as the seed stock is good. I just soak the pucks in a bucket, pull them out, line em up on a 10 x 20 tray, plunk the seeds directly in them and put a humidity dome on top. I recently invested in a seedling specific heating mat and that sped things up for me. As soon as the seeds break above ground and drop their casing I transplant the puck right into a party cup with amended light warrior - a soil designed for starting seeds made by the same company as OF and HF. No need to mess with the mesh on the puck, it won't do a damn thing to restrict the roots and was designed to accommodate them. It's be silly to manufacture a seed starting puck that restricted the roots.
On another note I'd avoid any jiffy pots or similar pots made from peat or manure, in my experience they're a terrible idea and will for sure restrict your roots.
it's a psychological thing eheh
