Northern Lights indoor/outdoor auto grow, extra long veg stage

So I've recently began expiramenting with growing since it became legal here in Montana, and one of my Northern Lights autoflowers is going wildly different from the others.

I started everything indoors under LEDs which I've later found out weren't putting out nearly enough lumens (1,500 for all 6 plants combined). After they germinated (cup of water soak & paper towel) I planted the taproots in miracle grow seedling mix and they all sprouted on April 21st.

After a slow veg stage that didn't yield much growth (which I know why now), 5 of the 6 started to pre-flower on June 1st (5 week mark like they were supposed to).

I gave 3 of the plants away, and transplanted 2 into larger pots w/ regular miracle grow potting mix that were flowering really well on June 10th (week 6). Today is July 21st and they are still slowing maturing and turning orange (week 12). They didn't do much due to poor light and me not giving any nutrients besides what were in the potting mix since I'm a noob. But the last plant in the bunch has been strange.

I planted the runt of the litter outdoors in my garden bed on June 10th. It hadn't began pre-flowering yet and was by far the smallest of the bunch with barely 6 small leaves on it. The next 2 weeks it rained all day everyday and had cold temps in the 40s and 50s all day and night and it didn't grow at all (surprised it didnt die). By June 28th (week 7) the rain finally stopped and it finally got hot outside, so it finally grew to about a foot tall and the fan leaves started getting much larger than my indoor plants.

Today, July 21st (week 11) the plant has blown up to over 5 feet tall and just went into pre-flower yesterday. I'm confused by it's late flower stage but assume changing its temperature and light cycles by putting it outside after week 6 did this. Has anyone else had this experience? I'm thrilled by its size and that it actually finally went into flower. The harvest will be huge if I don't mess it up, so if anyone has any tips from here on out it would be greatly appreciated! I haven't given the outdoor auto any nutes or anything yet.