The only thing I can agree with here (to some degree) is 'an animal's individual temperament'.
I don't handle/work with any of the snakes in my care. Most get picked up a few times a year. Baby Suriname boas go from open mouth hissing, striking and tail writhing just from pulling out their tote to coming to the opening looking for food within a couple of months. This happens with as little handling as possible.
Even when the babies soil their enclosure I reach in, pick them up, put them in a fresh tote that was made ready before-hand and slide the drawer back in the spot. One of the babies I have right now would hiss if a shadow crossed his opaque tub for the first month. For this little guy, I didn't 'work with him', I gave him his space and left him alone...no photos or anything. He is just like his sibs now...calm and looks at moving objects as potential food.
I've picked up 25 wild bull snakes in just one weekend...not one offered to bite. Most calm down within seconds of gentle handling and remain calm while I take their temperature/weigh/measure them. I have never restrained one and I have done this for years with them. I only recall one bull that made a real earnest effort to bite me and even that one calmed down without being restrained. No-one has been working with those wild bulls. I used bulls as an example because they have a reputation (from where I don't know because I haven't seen it).
There was a time when I thought handling would affect boa's temperament but the proven reality is that it isn't needed and it can cause real problems. I think some keepers struggle with young snakes (especially Suriname/Guyana types) because they can't keep their hands off of them...leave them alone until they gain confidence over the time they need. Of the 45ish baby Suriname boas born here (or the adults) none have ever regurgitated or been a problem to get eating. All of them have become calm within a few months and none of them were handled in an effort to force some desired behavior.