Heya Shed, apologies for missing out on the convo last night.
So I agree with
@bobrown14 in that I believe(d)

the roots hitting the bottom activates flowering. Recently, I had the pleasure of growing out my last Tyrone Special bean from Mephisto Genetics. The beans of this strain I grew before were in 3 gallon, the most recent was in 2 gallon. The difference between when flowering started was surprising although I must admit 2 gallons is the smallest I have gone.
Typically, the advice is to start in the final container. I have started in solo cups before and transplanted. When I do it, I’m just simply waiting about 7 days to transplant. Great white in the hole and on the transplant. I have never seen them skip a beat. Earlier I said to let her go but I’ve changed my mind. I would take the chance in your case. Worse that can happen is she slows down, but if it goes the way we hope I think she’ll like it.
You mentioned transplanting into a 7 gallon container. I’ve not grown in that large a container with autos. Largest I’ve done is in 5 gallon. I grow in coco, but I’m ready to start cooking my soil for Doc Buds HB kit. I’m going with 10 gallon final container sizes and making the transition back to photoperiod plants because of it. That reminds me, I need to get seeds started ASAP haha. Short-term memory loss strikes again! Peace!