Okay Observer, A few things my opinion only. Never by Auto, they are crosses with Ruderalis which is basically hemp. Flowering is simple, change your light timers from 18/6 to 12/12 (light/Dark).. period, that's all it takes. (auto-Flower would only be Okay if you are growing in Alaska, or some other place like iceland/greenland/siberia with long days all summer. You time it with preflowers showing and there is no problem. Super simple. I would identify your preflowers if you have problems. So would anyone with experience.

Second, I would get 4 of these "Spiral CFL - 65 Watt - 250W Equal - 6500K Full Spectrum Daylight" instead of the Metal Halide. I would get a pice of plywood that is about 1 meter square and drill 4 holes 2 inches diameter near each corner. Then buy 4 cheap One-Piece Incandescent Lampholder, Pull Chain, White. Mount these and wire them yourself with a switch. Hang it on a chain and move the height with ease.

The babies are too spindly, not enough light. They are stretching towards a too dim light. If you could get the glass cover and vent then place the light close enough, maybe. ( I would do what I say)

Third, FEM seeds are often Feminized with Chemicals. Learn to differentiate sexes. Period. If you stress your plants and they hermaphrodite you will need to know what you are looking at anyway. Besides you can tell sex with preflowers and before you invest time or money on them.

No need to flush but every 3 weeks which should only be 4 times before harvest.

Create a clone room and place this light you built there.

Keep your room at 21 Celcius Day and night. You will need to vent your room at night durring flower becasue they transpire quite a bit and the humidity in the room spike when the lights go out.

Get a couple small computer fans to blow air around the room, not directly on the plants, near them. This will strengthen your stems too.

Love your plants, really, it helps as we are all connected and they feel your love or your anxiety. You chose which to give.

I have more advice but this is enough for now. Good luck

I hope you watered right after taking this picture. Especially that center one, looks too dry. Again, good luck with all your choices.

Nice, I see you transplanted two. If you have plenty of holes in the cup you shouldn't really have an over watering problem.

Have you decided what you will be moving them into for containers yet? Will you step them up or move into the final container next? Each transplant has the potential to stress the plant, depending on how smooth it goes but there can be delays while the root system recovers.

These will do better in a shorter/wider container than a narrower one to avoid a root ball (root grow sideways more than down). I would suggest using a ph neutral stone, clay pellet, extra perlite, volcanic rock or something in the bottom of whatever container you have for drainage so you don't have root rot.

I hope your transplant went well.

I got to the point where I started them in the same container I would finish in. A bath tub. I got a dented one at the local hardware store for next to nothing and filled the bottom with Volcanic rock and ran a drain into a sump pump. The tub is awesome because it's impossible to have standing water in it. the roots grow sideways more than down so shallow and wide is better that deep but narrow.

Looks Good Observer. Have you inspected your pre-flowers yet? At what point are you going for 12/12? I would go into flower as soon as my preflowers showed up. It is a sign that the plant is ready for 12/12. You shouldn't need much more time in this stage IMO.

After all the years I grew, in the end I quit all of the LST and other "tricks" and just let them do their thing achieving 18 dried/cured ounces in a 2.5 X 5 foot room a stairwell actually, with a bathtub in it...

Is there anything circulating the air in the room? I used low CFM computer fans for an indirect breeze.

I would guess 7-8 weeks minimum after flowers start showing, 4-6 weeks with no flowers yet doesn't seem feasible unless you are going to harvest immature buds. I forgot they were Auto's. Do you have a weavers loupe or other magnifying device to inspect Trichomes, insects, whatever?

Also, I always made clones with the bottom 4 branches from each plant, very efficient. get some mothers rooting hormone and I used a plastic container and a germinating (heating) pad under it as a humidity dome. Maybe you are not interested because of the LST.

Makes me want to get going again...

Looks Nice... Growing more than one strain in the same space is even harder if not autoflower, trust me on that... Each strain has a different window and harvest becomes especially tough. Patience now. You keep mentioning smell, do you have a carbon scrubber? I used a carbon scrubber in the room and a Ozone generator outside the room.

Keep loving them

These plants are so strange. The two Dark devils started off similar all the way into early flowering. Now one of them seems to want to stay there and do almost nothing, the other has taken to expanding the buds and turning them a deep purple. The anesthesia auto is starting to stretch just a little and looks like it is about to start putting mass on.
I am going to be watering more often, I did not realize just how quickly and evenly my substrate was drying which probably led to the stalling on the one plant. Will get some pictures up within the next few days.

Next time you might think of adding lots of perlite.