I wish all of you great success with this.
Please be very paranoid about infections. Proper, well thought out scalp disinfection steps.
There have been some horrific cases due to defficient sanitation and it's the reason the microneedling-dedicated thread on this site is closed indefinitely.
No swollen lymph nodes should happen.
at most you would need 0.5mm for Choi, superficial stuff, not the hardcore 1.5-2mm stabbing yourself in the head. In anycase people should be hygenic regardless.