Nobody has ever cared at checkouts, but my state requires that you use a stylus pad to enter your signature for your driver's license (it gets printed right on the card). In early 2020 I used my driver's license renewal as an opportunity to update my voting registration (I had just moved), and apparently that stylus pad signature ended up being my "check" signature for my vote-by-mail for the 2020 election. Of course, I had my ballot bounce and had to provide further identification, because there's no way I'm getting my signature from a stylus pad to match one on paper.