Not to worry, but I dont think its worth topping an automatic plant. Let them just do their thing.
Yep, my observation as well. If I grow autos, I LST 'em early. LST = Low Stress Training: Bending down the highest branch to expose more light to the lower parts, allowing the smaller, lower branches to catch up. = more new growth = more nodes = more bud sites! Without shocking the plant at all.
Have a look at @happilyretired autos!
And if it were a photoperiodic plant, I usually wait till it has 5-6-7 nodes then top it down to 3 nodes remaining. This way the plant is strong enough to coop and you don’t have to worry. She’ll get over the shock of it better. (More roots, thicker stem, easier to transport food, better recovery …)