Outside is a different context... A lot of stuff done inside relates to the fact the distance from artificial light makes a huge difference in intensity of light. translating that outdoors would only relate to areas of heavy shielding, as being 1foot or 500ft further from the sun is irrelevant to intensity of light for a plant. So, pruning off some inner growth that is mostly shaded/shielded won't hurt you too much, but don't cut off growth with good exposure. That's just cutting yield off. Don't worry about a level canopy outside... Worry about exposing as much leaf surface a possible. Avoiding over congestion is still a good idea for both indoor and out. if lollipopping to move foliage a safe distance from the soil surface, i'd say you are fine. plenty of airflow there.

Honestly, the same reasons for lolliping is more of an indoor thing. The sun rises and sets in a 180-degree arc; therefore, the plant does not need to be lollipopped as vigorously outdoors. It still helps to direct growth ofc, but what I'm seeing looks adequate for now. You don't want to remove too much, even if the leaves don't look like they are photosynthetically running at 100%; they still perform critical daytime cellular respiration. Carbon fixation must match assimilation. Dont make life harder than it needs to be.

The plants look good and healthy. For me it looks like a reasonable lollipopping, I would not go further for now. I learned, that lollipoppiing makes the most sense in week 3 of flower. Until then the plant puts energy in trying to grow new leaves and shoots in that "useless zone" wher you cutted it away. So I would let it now how it is and check for the need of a second lollipopping round during the 3rd week of flower.

When I grew my Durban it sems like a really forgiving plant to train and responded well to topping. but outdoors lolipoping is less important. Also of grower manipulate the topers to make fat tops. think of a double lay scrog net in a grow tent but on its side in a cylinder shape. they pull the lowers outward and get a globe shaped plant with tops in 360 degrees. They are looking good though. Depending on the plant 6-18 inches of lollypop is appropriate just depends. Common times for this sort of trimming is week or two before flipping to flower to give time to recover before changing another variable like daylight. Then 2-4 weeks after they have been in flower.

I never hurt my own plants, I don't have enough lateral space for them, and the maximum height allowed is 2.5 meters. Unfortunately, I can't give you good advice. Since you have several plants, you can experiment with one to see if it works.

Hey, yeah, the lollipopping at this point is definitely possible, I would always do it just before the plants start stretching and maybe once again after the 3-week stretch phase, especially during the rainy Sept/Oct in Germany, because you want a more airy canopy instead of dense in the middle... the risk of mold is just very high at the end of the season.