We have a safe deposit box that needs to be drilled for non-payment. The box holder is a legal entity. Do we need to complete an SCRA search of the individuals behind the legal entity?

I do not believe you would need to search the database for a Legal Entity, only natural persons.

https://www.bankersonline.com/qa/drilling-safe-deposit-box-under-scra

https://www.cuinsight.com/recent-doj-scra-enforcement-actions/

If the individual behind the legal entity is also individually liable on the safe deposit box lease then I would say they are entitled to the SCRA protection if they are an active servicemember.

It takes all of 5 minutes to run the check....IMO....5 minutes well spent if it prevents a possible SCRA violation which in turn can produce a PR fiasco.