in future, topping can help cause more axillary growth. When they are very stubborn, i think LST works best... get teh stem horizontal after it has enough axillary buds to warrant the stress. If you keep it level, the growth will spread evenly along that level branch. If anything outpaces or has some extra additional growth to start, you can bend those down temporarily to break apical dominance.. .this will shift growth away from those taller spots... release them when other growth catches up.
the tallest part on plantn will always pull the most resources. it has no centralized nervous system. So, simply keep things level or bend down to manipulate growth rates in different areas of plant. topping will cause grwoth below that node to increase, but will quickly focus on the highest growth buds.
Apical dominance... it is a tool for manipulation of plant growth. It's got simple rules. use them to your advantage.
autoflowers are not always the best to train in such ways. too much stress may cause early flowering, for example. topping may reduce yield depending on how much growth is occuring after that point, which we can only guess at. In many cases you'll do best with an autoflower simply by letting it grow naturally with limited manipulation.