Both years, I didn't cool mine. The first year, the only change I made was in changing the light cycle slightly from 12 hours to 10 hours for about 6 weeks and was successful in 2 out of 2 Boa pairings (a Bci and a Dumeril's). Last year, I made no changes whatsoever and had just as good of results. At the point of my heat up, I had 4 litters on the ground, 1 that had slugged out, and had 3 other gravid girls... which accounts for the 8 Boa (6 Bci, 1 Bcl, and 1 Dumeril's) pairings I did.
That being said... your set-up is most likely different from mine... I have a separate building for my reptiles with no windows and is maintained at 78 degrees year round.
I have found it best for me to ask for the opinions of multiple people and to take each into consideration, but ultimately, I know not everybody has the same set-up, so anyone that makes a blanket statement saying you HAVE to do it a certain way... well, I just take it with a grain of salt and end up doing what I think is best for me in my situation - which typically involves taking bit and pieces from more than one person.