Are you shaky or unstable when drawing a 70lb bow? If you have no problem drawing 70, then why not? Do you perceive that you can't handle 70lbs, or do you legitimately struggle with it?

Another big watch out to keep in mind when increasing your draw weight is your arrow spine. If you are shooting .400" spine shaft, you may see issues when you bump up to 70lbs unless you run a short shaft. Even a .330-330" shaft may not handle it well. I would assume since you are 25" draw and 75grn tips, you are running short arrows, but that may not be correct based on your arrow weight.

Question I have for you, unrelated: what is your calculated FOC with your 354grn arrows and those light 75grn Muzzy's?