Questions About Autos

So I have a FOG Auto on Day 40

The info I have on this says it flowers in 75-100 days. At day 40 I am expecting it to flip soon. Question 1 is why does it seem so short?

I am 90% sure it's just because my LED tent isn't top tier. I've got a MarsHydro 600w (the old blurple kind, not their new white light..got my eye on it tho). And a Rapid LED 120w logic puck. Theoretically good for my 2x4 space, but obviously it's no Spectrum King.

My other thought is that I went too light on nutes. I definitely go light on nutes, which coulda bit me in the ass with the less-than-killer lights.

Question 2 is general. Do autos go through the same stretch period as photoperiods? If so, I think it might still do a bit more now that it's under the HPS.

Thoughts? Tips? Tricks? All appreciated

Lights: MarsHydro 600W + RapidLED 120W logic puck
Now under 600W HPS

Nutes: Fox Farm Grow Big [6-4-4] (1tbsp per 2gal in 6.5pH water every other feeding)
Couple hits of Microbe Life All In One [0.5-0.5-0.5] (2 tsp per gal for micro nutes)

Medium: Fox Farm Ocean Forest and Promix (about 70/30 ratio)

Here are some pics from today

After it adjusts to that hps it should take off, you can run some longer dark periods to speed it along (depending on the strain) could help it adjust to the new light also