Years ago I was at Taverham Mills testing baits against each other, steamed versus boiled, (various boiling times) blocked and cut (the whole block being cooked in boiling water then cut into squares), and just dried.
The results were inconclusive, not a failure because the fish loved them all, clearing the area within minutes of a handful of bait going in.
If anything the only failure was discovering that edge pieces of blocked baits floated.
It was then down to breakdown time, and steamed and boiled baits took longer in a large tank break down than the other forms, because of the harder outer skin.
Final point, there is absolutely no need to boil a boilie for any longer than 2minutes, it is down to drying time on how hard they are.