This doesn't directly answer your question, but... When dealing with 65% poly/35% cotton, and with triblends, it has been my experience that cure temp is a big factor to watch. I've said this many times over, but for printing white on these blends, our go-to is One Stroke's ELT-S. Other colors are either low-cure out of the bucket, or get Low Cure Additive mixed in. It's really helpful to keep cure temp around 300, and consider a peak of 320 as the ceiling of your "safe zone." (And if you're not dealing with a short dryer like we are, you could move that down about 10 degrees.) With this approach, I have rarely had to worry about a strong blocker base.