I have done some experiments to speculatively confirm some of the Reddit rumours.
How many Sleeper Nodes do I need to open to get a Braytech Schematic?
Between one and four.
Is the Schematic drop limited to one a day?
In my tests, yes. Once per daily reset. Changing in update 18.104.22.168 on Sept 3rd 2019
Does it matter which nodes I open?
Does having the weapons you already have make a difference?
Not for me. I had three weapons in my inventory (AR, Sidearm & Sniper) and got duplicate assault rifles. You're just getting a Warmind Engram, so it's down to RNG.
You'll want to farm around 12 Resonant Stems per daily reset.
Small sample research data
- Saturday - Opened three nodes, got a schematic on the third one.
- Sunday - Opened three nodes, got a schematic on the third one.
- Monday 1pm - Opened six nodes and did not get a schematic.
- Monday 6pm (After daily reset) - Opened one node and got a schematic.
- Tuesday 10pm (After daily and weekly reset) - Opened 4 nodes and got a schematic.
- Thursday - Opened one node and got a schematic on the first.
- Friday - Opened three nodes and got a schematic on the third.
- Monday - Opened one node and got a schematic first time.
I have marked this as accepted, because this evening I got a Niflheim Frost to complete my badge.
Destiny 2 Update 22.214.171.124
Braytech Schematics are no longer limited to 1 per day, per account
Braytech Schematics have a 25% drop chance when opening any Rasputin Data Cache
The four Braytech weapons offered by Ana Bray, and also tied to the Wayfarer seal, now have a greater chance of granting a weapon you do not currently have.