In many MCU movies and TV shows, whenever a Skrull changes his/her physical appearance, their clothes changes too. Is clothing a part of their physiology and is it referenced in the comics or elsewhere?
It's not shown in Secret Wars as far as I know but they have access to a form of nanotechnology.
This is evidenced in Captain Marvel.
When we first see Talos take the form of the surfer girl his initial clothing is absorbed into a purple gem on his shoulder and new clothing formed from the same source.