Mine have been at 1250 ppm CO2 and they did not blow up as much as I expected with the exception of the monster. That was was large and got crazy.
I'll have to do a pic update on the girls tonight when they goto sleep. You can really see that the smaller ones filled out, but did not even double in size legnth wise. I do not know if this is a bubba 98 thing, that it needs a solid 3-4 week veg after rooting the clone. Like you said waiting another week is not big deal, so they stay in the veg buckets a week longer and the current crop just gets extra amber trics, heheh.
Yea, top of cage sounds perfect. They are gunna get huge but the bubba can for sure handle it. Its one of the easiest strains to grow, super vigourous rooter.