This is because your streams with ids patname1 and patname2 uses the same (default) orbit 0.
And something like delay is a so called "gobal effect" and applied to the audio result of an orbit.
You need to specify your orbit to separate the result of the delay like:
p "patname1" .... # delayfeedback 0.2 # orbit 0
p "patname2" .... # orbit 1
Now it should be clear, why d1...d'n is defined in this way:
-- defined in BootTidal.hs
d1 = p 1 . (|< orbit 0)
d2 = p 2 . (|< orbit 1)
Oh I see, this may be a little bit confusing, it has to do with the orbits and their busses implementation in SuperCollider, as otherwise I don't see any point of mixing two patterns.