I am actually tracking this.
I have 1007 out of 1082 blessings (93.1% complete). I have all lvl 1 blessings (got the last one earlier this week), all but 2 lvl 2 blessings (both on the sapper shovel, hate that thing, least common weapon in the game), all but 5 lvl 3 blessings, and the rest are lvl 4s. I have at least one level of every blessing except one, Inspiring Barrage on the flamer. I have 11 weapon categories maxed out and another 11 are only missing a single blessing out of the 41 categories there are.
I have 764 hours in the game but I’ve been playing since the POB and couldn’t collect blessings for a big chunk of that or was under the impression that we would be able to combine blessings or share across weapons so a lot of my pre-Patch 4 collection efforts were wasted.
It’s pretty clearly a slog. Things went pretty quickly up to about 75% completion. I’d get a handful each play session and would even have to pass some up just in the regular docket store because my dockets were exhausted. Now, some characters can go the full week without seeing anything in Melk’s and just save the Melk money for next week (or be like my veteran today with 5 unowned T4 blessings in the shop all at once that I can’t afford, crap). A bit after I started collecting it hit me that this would be an effective and in-flavor method for governing weapon property unlocks and I made a post to that effect a while back. Sadly, they didn’t bite.
For anyone interested in the out-of-game blessing tracker, you can find it here.