Whilst the increase to Common Blueprints at Tier 1 is welcome, I don't think tweaking the numbers will really help, as the current rewards system is flawed, at least when it comes to Blueprint acquisition.
To acquire a Blueprint for a character, you have to first wait and see if a Blueprint reward is on rotation.
Then, if you want to play as a Raider, you have to see if the character you want is available for the mission itself. For example, Lycus is unavailable on Hanging by a Thread, Ayana is unavailable on A Low Blow, Schneider is unavailable on In Medias Res, etc.
Then, you have to consider whether the character is a good fit for the map. Some maps tend to have objectives and bosses that are far away, so some characters can't really do much to help the team. For example, Ayana can't really do much to damage to Uras' ganglions, Marmalade's weak points, or to the 5th Council's weak points, so it would be a bad idea picking her on those maps, even if you wanted a Blueprint for her.
Then, if you get to the character select screen, you have to hope that no one picks your character, else you're dead in the water already. I've heard players complaining about others on their team going AFK, leaving, or worse, if they don't get the character they want at the beginning. Moreover, if you're playing with friends who are in the same Aequilibrium group, and you all want to play as a certain character, then there are going to be problems. This is somewhat less of an issue for newer players than veteran ones, but it's still a problem.
After these hurdles, you then have to win the mission, and hope to get a good score. Unless your teammates are kind enough to bring some Treasure Hunter weapons along, there is no guarantee that you will win the roll.
Then, even if you do win the roll, you have to hope that the weapon Blueprint is one that you actually want, otherwise all this hassle has been for naught. Most characters have 2-3 Common Blueprints, and some have 2 Rare Blueprints. As such, your chances of getting a specific Blueprint can sometimes be 33% or 50%, even before you roll on the results screen.
The game does recognise if you've been given a duplicate Blueprint, but you get nothing if you get a duplicate. Moreover, Blueprints you already have are not taken off the roll, which can be annoying if you get seven Granny's in a row, as some players have experienced.
It would be much better if players were rewarded with Blueprint tokens, that they could then use to acquire whatever Blueprint that they wanted, rather than be awarded with a random Blueprint for the character that they used on that specific reward map. With a token system, players can use whatever character they want, without having to fight with other players. Furthermore, they wouldn't have to suffer through acquiring multiple duplicate Blueprints, as they could use the tokens to get the ones they want.
You could also have Blueprint tokens randomly drop on any map, even if it's not a special reward map. Perhaps give players a 5-10% increasing chance per win to get a Blueprint token, with the counter resetting when they earn one. That way, players would have a reason to keep playing, even if there are no Blueprint tokens available for them during their reward rotation. As it stands currently, a lot of players just check to see if they have a Blueprint reward on a rotation, and once they've beaten that map, they just log off because they have nothing else to do. Having more players online would help with queue times, so giving better incentives to keep people playing, even if they don't have any special rewards on rotation, would be a good thing. Perhaps also give out tokens to players who win as, or against an Antagonist.
As an aside, at least at Tier 1, there is little reason to complete a map whose 'one-time reward' has already been acquired, as you only get 'Gold (Medium)' or 'Faction Points (Medium)', which isn't very much at all. It would be better, in my opinion, if the special rewards were in addition to the usual rewards at Tier 1.