Baby boas and juvenile boas do best in rack type or non-display type cages. It may be they need more privacy, or perhaps there are other reasons.. it is usually easier to control conditions in the racks.
Without making any judgements on you or your experience I want to point out that many times when I see caging designed and or built by persons with little experience with boas it appears the cage was built and set up for the keeper, not the boa. By that I mean that it allows for ease of access, good viewing, etc. but is less focused on the important things.
The best boas cages may be easy to access and give good display but the important considerations are that it is escape proof, provides no way for the animal to suffer an injury, is easily cleaned, will not harbor mites or other contagion and can provide the proper temp gradient and humidity as needed.
Long term using racks or something like a rack is cheaper too, you don't have to supply a small display cage for little boas, and bigger ones for adults. When they are around 3' they can go into a complicated and expensive set-up.
Just my thoughts.
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Gus
A. Rentfro
RioBravoReptiles.com
"Quality is not an accident. Perfectly healthy animals are a minimum requirement.. everything else is just salesmanship" gus