Yes,
That's really too bad and we seem to have a similar situation here in the states with the Burmese python although it is very overblown. The Florida Everglades has a population, but they are not spreading like the media states. Boa constrictors and a few other exotics are included but there are more things going against them naturally than going for them.
Usually the animals are put down here as well.
It would be nice if you were able to keep boas there, as I think responsible keepers would never have issues, and as you said, even if one were to make it out, climate would more than likely ruin its day in the long run.
I am fascinated with boa constrictors and carpet pythons. I have a few other snakes that I fancy, and not surprising they are from your country. I think the scrubs are possibly my favorite animal, maybe followed by the olive python.
The only other constrictor I'd consider outside of those, and what I already have would be a dwarf or super dwarf reticulated python.
Your post was very interesting, and for the most part, that is how 98% of captive boa constrictors behave.
I'll bet you come across a lot of interesting stuff doing what you do!