Hello again. I have 4 plants passing 6-8″ tall, looking a lot like the picture you posted above that are getting a lot of new growth. Should I trim any part of this plant to reduce shading to the new growth? Like potentially unproductive fan leaves??

Nope,depending on how tall you want your plants, no cutting yet. Get them into their final destination containers though, before you know it those dixi cups will be root bound, theyre getting there already i bet. How much space up do you have to grow?
If you have 4 feet of vertical space top it at 18" or so, he more space up to grow you have, the taller it can get right? I personally dont trim until theres a problem with what has to come off, ie. anything dead, yello, or other than green and pretty. My advice, experiment with ideas, but take it slow on the cutting, if you do at all.

My tent is 80" tall so 6.6 feet but my light hood would take up over a foot of vertical space if it was hung all the way at the top. Right now it’s about 3.5-4 feet over the top of the plants. Also, the bigger lower leaves are yellowing a bit on one plant…take em off?

I wouldnt worry too much about the yellowing leaves. They are the lowest on the plant and usually the first to go. I do agree with Heartodixi about getting those into some larger pots. I responded to some of your other posts about the perlite and those were in the solo cups then. If you are catching any new growth, or height etc…they are ready. If you are only planning to do those 4 plants, I would get them into some 9 gallon bags and once you hit a week or so in the bags and they are rooting good -top them. Wait 7-10 days then top them again. Before you know it your 4 plants will look like 12 and when you achieve the height you want you send them into flower. Remember that when you change the light cycle to flower, your plants will still continue to grow vertically and you should count on them to almost double in height. Say you only have 8 feet to grow in and your light takes up 1 foot of those 8, you have 7’ remaining. Cut that available 7 feet in half and that is approx how tall you should veg. You will want to veg your plants to a height of approx 3’ allowing yourself an extra 6" or so wiggle room. Once they reach about 3’ you can send them into flower. Once in flower, you will need to supply the plants with a proper flowering feeding which would supply more P & K into the feeding and less N. Just by doing these simple but effective things during your grow can potentially double your yield.

Make sure to factor in the distance from leaf tip to light as well, if thats a 400W bulb id think 18" of space from bulb to tip. You got as much up as i have to grow in, not so much wide though…
Id get those in their final container NOW, i use well drained 5 gal buckets, top them once at 18-24" ffom the top of the container. At three feet tall switch the lights and flower.
When you flower spread the plants out so the tops get as much light as they can. Then, look at all the stuff underneath that doesnt get much light, and; starting from the ones the most in the dark… (Pause to brush up on cloning) use the shaded branches to practice cloning and hammer down the plantsbfor the next cycle. Thats a suggestion ;+). They should be good and ready at 5 feet. You might need to hang little fishing weights suspended by bent paperclips to keep the toppest parts of the plant away from the light, laugh, but it works, and soon the weight of the flowernis enough to keep em bent over.
Wait until the leaves arent green anymore, even busted up, green still works. Once theyre in larger pots you can clip the tips back, just wait till theyre transplanted and happy before hand.

Hydrored <---- i agree with.

Thanks so much guys for all the input. I transferred into my 5 gal smart bags tonight. I also switched the dark period to 11am-5pm since that’s the hottest part of the day, which is hot in Arizona, to try and lower the average temp. It has been sitting around 84 but I read that may be too warm?. the humidity I keep at 50% with the lights on. Same humidity with the lights off but temp drops about 6 degrees F. Are these good condition? How much should I water them at once in the 5 gallons?