First off welcome to the forums.
You've made quite the random jump from species to species. That's awesome but I will say that while you've not encountered any bad experiences with any of your snakes so far you should still be cautious. This goes more towards your dumerils boa that is 6'. I know they can get pretty hefty so you need to take caution when dealing with him. I always recommend the rule of once a boa or python that get's to a decent size of 6' and can get thicker around you should always have a 2nd person nearby when you take them out. While some people may be able to stop a 6' snake from coiling all it takes is for you to get caught off guard and you can end up paying for it or putting a bad mark on the hobby. So please take caution when dealing with your Dumerils. A general rule of thumb is that anything over 6 ft you should have somebody nearby.