I've not used this exact product but I have used heat shield in this location & yes, it did help. Have you looked at the gold version? Worth a few extra BHP for looks!
Interesting fact, Zircotec ceramic coating was invented to control heat in the nuclear energy sector. Then someone worked out that the same process had applications in motorsport & now their ceramic coating are OE to a number of high end supercar companies such as Pagani and McLaren.
I've used a lot of Zircotec products and have no problems recommending them. Shop around though as better prices can be found.
That said, I've never had paint in this area bubble up due to heat alone. Before you apply a big sticker, which this is, over the problem are you 100% sure there is no rust or moisture behind the paint?