Autoflower not flowering fast enough

Hey all,
I'm growing 'Shortstuff#1' at the mo. Got 5 on the go in a small space. Firstly, the reason I ordered these was because they're not supposed to get any taller than about 38 cm. Mine are now around 3 feet tall. I've had to bend the shit out of them to keep them from growing into my light. As I'm growing 5 in a 70cm by 70cm tent, I guess they stretched in competition with one another. But my real issue is that they're currently just over 5 weeks from sprouting and flowering seems to be happening slower than I'd like. Aside from some yellowing at the bottoms of the plant, which I'm working on, the plant seem pretty healthy. I noticed the first signs of flowering (little white hairs protruding from the internodes) at about day 16/17 from sprouting then there was that crazy stretching period (which has now come to a complete stop). In the 2/3 weeks since then the bud development has been somewhat unimpressive. Most of them are just tiny clumps (hairy white balls) no bigger than the tip of my thumb. Am I being impatient or should things be moving faster at this point? Supposed to be an 8 week strain but I'm not really bothered about that. I just want them to develop properly. Any ideas welcome. Here's some info on my set up:

grow area: 70 cm by 70 cm by 160 cm (H)
Light: Viparspectra 450 LED (Actual 200W)
11L Air Pots
Plant Magic Plus soil with added Perlite
Advanced Nutrients Sensi A/B PH Perfect
Bottled water (PH 6.2 at source)
Extractor and Carbon Filter
Circulating Fan
Day temp: 22-26C
Night temp: 18-19C
Window open for fresh air
Watering frequency: When top inch or so is reasonably dry (3/4 days usually)
Currently on bloom nutes: 1ml per L
No additives - too expensive

i would give them a full day of darkness, see if that kicks them into overdrive. they may be autos, but the flowering mechanism is the same, autos just hyper produce the flowering hormone. maybe that gene didn't express so well with these.

First time I've heard that. Thanks for the info.

If you've supercropped that will have slowed everything down by a week. More light more growth, you always can get a mad stretch with led

Interesting that you mention supercropping. 4 of the plants I bent over ended up with curved stems. However, it wasn't until about a week later that I noticed the stem of the 5th plant had actually creased like a fold about half way up the plant. I'm not too sure but If info online is correct, I've actually supercropped this plant accidentally. Strangely, this plant seems to be ahead of the others and the main bud is exhibiting impressive growth compared to the others. I'm almost at 6 weeks from seed now, plants still healthy, dialled in the nutrients and feeding so no more yellowing climbing up the plants but I'm wondering what to expect in the coming weeks and if they're going to fill out considerably or not. I hear what you're saying about slowing down growth by such action at such an advanced stage, makes perfect sense. I just hope I haven't affected my final yield too much.