I've raised various kinds of snakes (no BPs though) and done it both ways: leave them together for a while, separating them at LEAST by the time they shed, or
separating them immediately. It doesn't seem to matter, the only exception was the rosy boas I used to raise...many of them were so feisty (biting me & each
other!) so I had to separate them at one day old, & many of them even took pinkies then (before shedding)??? Sassy ones, definitely would have survived had
they been wild, & fyi, both their parents were unrelated wild-caught rescues (-unwanted by original "owners"). You think of rosy boas as being so mellow.