Talk with DDM Works, or other Forum People... Critter and Helios were running Stage 3 for YEARS and thousands of miles. I do not think DDM would put out an upgrade that would intentionally "detonate" engines. Dave just cares too much about the KAPPA community and the cars in general.
I would already be ready to do a full engine build if necessary for the LE5 (Rods, Pistons, Springs, Rings, Sleeves, Head, and other internals) if you are going to do any boosting. If you are gonna go, GO BIG!!!
In the end, Critter always speaks the truth on this topic, "If you are gonna play, you have to be willing to pay." I live by this, it is the soundest advice for ANY car modifications.