Heyo! I just posted this on a similar Reddit thread:
We’ll be having an Itemization Overview dev blog with more details coming out this week should everything go as planned. I’ll tell ya now though, the general advice will be to keep your guns so they can be sacrificed. When it comes to the amount of blessings, if you have all of T4 and about 1/3 of T3, you will already be maxed out at mastery for that weapon family.