Border thickness as variable

[ssimo3lsuhsc]

Hello!
I'm wondering if it would be feasible to make the border thickness a variable? I'm using ABC because they overcome a shortcoming of the Bootstrap custom checkboxes. I'm designing for print. The checkboxes print out nice and large, but their 1px borders are very faint. I'm wondering if the border thickness can be made into a SASS variable on all branches so that the user can change them to 2px if he or she so desires without having to fork ABC. Thank you!