I'm guessing the pattern is probably a custom job made from one of the many available merchant resources of knit fabric. Maybe even from something like this.
https://www.renderosity.com/rr/mod/bcs/knittings-vol-2---a-merchant-resource/50960/
i mean, the character is from luna3d and they seem well versed in making clothing textures, i.e. the nightflyer set brom rox mentioned.
oh duh, that pattern is actually shown as one in the promo pics for the main outfit, just not with the fluffy cuffs