I’m on week 8 of my first grow as well, and I did LST on all my plants from weeks 3-5. It was very easy (but anxiety provoking) but you just have to be careful, go slow, and stop doing it once they start to flower and the branches stiffen up.. It will increase your bud sites and likely lead to a higher yield if you do it right. I’ve attached some pics of my LST’d plants for reference. All are about 1ft tall, but as you can see are all bushed out with lots of good sized buds. I did this without ever topping any of my plants. Just a thought, maybe try it on one or two of your plants so that you can see the results you’ll get from it. You’ll be shocked at how quickly they grow and send up new bud sites once you bend that plant over.
Regarding your soil- Is happy frog a hot soil? Or is it low in nutes? I have my plants in bio bizz light mix (which is basically inert) so I add all the nutes to the plants. It gives greater control over what the plants get. It’s important though not to over feed your autos as I gather that they are more nutrient sensitive than photo plants.
Let me know if you have any more questions, I’ll help ya any way I can.