I have food allergies and sensitivities, so I am always extra cautious when I go to a new place. The folks here took my issues quite seriously, checking ingredients on their special sauces and making sure I knew which items to avoid or which items could be modified to accommodate my food needs. They made sure to use a separate knife when cutting, spreading sauces, etc, to avoid cross contamination. The gentleman we were primarily working with to order said he cooked in the army and had to go through rigorous food safety training there, including managing food allergies for their troops.
Grinders also has a gluten-free breading option (my issues are with dairy and pepper [the seasoning], but the GF bread is also DF so I was able to eat it without issues). Seriously, I can't express how grateful I was for the level of service we received. I don't live in Columbus, but I've found a new sandwich place when I'm there with my boyfriend, and we are both happy to have tried this spot!