Flowering Early- Advice on how to still maximize growth?

In Southern California. Got 6 clones from "Clone Guy Industries" at a weed store and didn't know I needed to give them extra light at first, I now understand they need 16-20 hours at first to help them transition from indoor to outdoor. I started them inside in mid April for a couple weeks then put them outside around May 1st. They've gotten 10-12 hours of light all of May. I noticed about 2 weeks ago they are starting to flower. Since I noticed I've been turning on an outdoor flood light so the plants are getting closer to 18 hours of light/day. They are still growing in height and also more flower is appearing daily.

I am hoping for gigantic plants so I think my best bet is to get new clones and start over since it's still May. But what do I do with these plants?

1. Main Question- Is it still worth transplanting them into larger bags? They are in 5 gallon now, I had hoped to move to 20 gallon, but now that seems like overkill. I could still move them to 10 gallon but not sure if it's worth it?
2. Should I keep giving extra light and hope they stop flowering? How long should I do this?
3. I'm still using pre-flower food (Foxfarm) instead of post-flower food. Is this okay? When should I switch?

Bottom Line- How much bigger you think I can get these?

Thank you!

If they dont turn back & go nuts they’ll continue flowering into not much more than they are now. Leave them & see what happens & go back & see your clone guy get a few more put them in now & nurture them to gigantism

these are little... could put them indoors under 24/7 revegg but need confirmation from "that weed guy" they are not automatiks

Should have ran them indoors under a full 18 hour veg cycle - outside they only got about 12 ( flowering cycle ). You can tell from the obvious lack of lateral growth.

And here we are.