Also, what it sold as a "colombian" boa in a petstore, is probably not even from Colombia but still a B.c.i. local of some sort.
A female if feed on a weekly schedule for the 1st year and then every 2 weeks after that will likely never pass up the 7' mark and will be a lean and very healthy. Obese boas have many problems which is why I recomend feeding enough food to keep their body shape at a good level and not much more than that. I could feed my 6'+ female every 3 weeks and she wouldn't be considered an unhealthy weight.
Also, there are some localities of B.c.i. that only get to 6' tops like hogg island boas and most other island localities as well as some Central American locals.
Hope this helps and makes sense to you