Mandarin Cookies R1 V2 - Custom Living Soil

Not much. It can't take in enough nutes to do anything but cannibalize itself. A minimal amount of paling is fine but you don't want them to eat themselves too much before they get some roots. Use Bti to avoid gnats and more, if available in your area. "Mosquito bits" and dunks are the brand i know of. But anything with Bacillus thurgenisis (spelled wrong but close enough) will work on larvea and 100% safe for you or pets. I use bti pre-emptively. You never know when a bale of substrate will bring in a bunch of pests from the store. Give them weak light and low VPD until they exhibit signs of growth, and improved turgidity (they stand up straighter with greater sustained water pressure inside the plant) as far as how much light.. just make sure they don't pale too much or fall over trying to avoid the light. High humidity slows transpiration (low vpd). This will reduce stress on the plant and allow it to form roots more easily. Unless you live in a very humid region, a humidity dome is very useful. They key is not giving them uninterrupted darkness for 10+ hours (flower cycle / chance for revege etc), which is easy enough to avoid. Can they root simply plopping them in some substrate and leaving by the window sill? yes, but success will be lower. Always take more cuttings than you need. Sometimes you'll have a 100% success rate, others you'll encounter a stubborn genotype or maybe it's not as healthy as normal etc... Lots of things can reduce success rate. if you take 4-5 cutting you could just leave them on a counter and at least 1 would survive, lol.

I have played around with layering, not quite the way you have done it, but not too far off. My living soil was doo dense, so I added coco and perlite to it to lighten it up, but was worried about it still getting too saturated in my larger pots (regular plastic, not fabric). I put a layer of coco and perlite alone in the bottom inch so the roots that got there should never sit in stagnant wet soil for long and I added another layer around the middle also about an inch so when the plant is young it can easily access airy pockets easily even if the living soil is a bit on the wet side. It worked quite well and after the plants finished, I saw their roots had spread more strongly in those airy layers while still having access to the nutrient in the living soil. I think your concept is fine, but I would maybe worry about the ratio you have of living soil to inert medium. If the plant stays small it should have enough food, but if you grow a bigger plant, you might need to start feeding more seriously than you normally would to make up for the lack of food. It will also probably dry a lot faster, so you'll have to water a lot more. Not a problem, it just seems it is going to make you work harder for the same result. I'm not expert and some of the things I've done may be really silly, but it worked for me and I grow large plants in those 30l pots without any problem. I just top dress with compost at the start of flower and use FPJ's I make myself and some epsom salt now and then. I would personally move the sand down to the bottom 1/3rd or 1/4th and have more living soil and less inert medium, but try it out and lets see how it goes.