Can I top my plant while doing LST age is 30 days

You can do anything, BUT will it bring proffit ????? Lst is good, but people still do mistakes with how, when, how long, many things to know and follow if you go that path. Topping is even deeper, you have to grow big plants, know how they behave, how they grow to do any heavy manipulations. I think topping only for comercial big grows. We simple growers can give more time, love and TLC to plants, so by toping you just stop your litle girl, let her run, LST her around pot, when top is going around pots verge. Top is at place, he grows, you bend and tie, he grows you repeat. With rest of branches you fill other parts of canopy. If people would just let plants grow, i can make bet that 90% would have bigger results without toping, defoliating or even LST.