Should auto-flower plants be topped?

I wouldn't top your autos. Autos have a pre-determined life cycle and therefore only little time to get over a plant-stressing measure like topping. As a few already mentioned, the long node distance is due to light deficiency.

No, too late for topping, besides it is not a good idea with autos anyhow. The stretch could be due to the roots finally getting some decent room to explode away - freedom! Those tiny pots you had them in are only big enough for about 2 weeks, 3 at most.

My answer is an unqualified NO... autos don't like to be messed with that much and topping is highly stressful to the plant - she may not recover in time to "do her thing." Since you say they've only been outside for a week, I think they had insufficient light indoors and were struggling trying to find more. Given that they are now in sunlight, I think you'll see massive changes in them - and all for the good. But please, do. not. top. !!!!! Good luck!

** relative to time of year too.. "Daily light integral region map" but include your locale... here is a map of USA https://endowment.org/wp-content/uploads/2018/06/New-Daily-Light-Integral-Maps-POSTER-Feb-201811-resize-1024x685.jpg

topping won't help... this is due to a lack of light. I'd just let it go as-is in such conditions. the only way to shorten internode is to provide more light. topping will only result in axillary growth that will be spindly and stretchy for same reasons as before. your region has an expected DLI... try googling to see how much light the sun provides... if it's closer to 20 than 30+, that is very likely why you see what is occurring.

seems lika a long vegging auto as they barely have started flowering at day 50 as it seems. you should try topping this cultivar next time definitely and probably transplant into outside much sooner so it can grow big and tall and wide with unconstricted rootspace. either way its all experience and they look healthy so peace!

Well, you'll get a mixed bag of answers. Its all about timing with autos. So the goal of topping is to max out on energy used to make more nodes and keep building up a base. So when topping an auto you need to get it in a early as you can to max out on that energy so it goes to the lower nodes and makes decent enough growth before it flips. Now when topping, you only want to top once. You see ppl topping many times, with autos you just don't have the time. So as soon as you can clearly cut above the 4th or 5th making sure not to cut too low as you don't wanna cut the growth that's coming up. So aim of the game is to v get it in as soon as you can. I've had pretty good luck with topping above the 5th nodes. Good luck