"PolySign's objective is to become be a leader in the growing digital assets space by providing institutional-level custodial and infrastructure support to a broad array of asset managers and exchanges."
https://www.apollo.io/people/Ian/McEachern/5aa8e09aa6da984f8d0ac955
https://www.apollo.io/people/Ian/McEachern/5aa8e09aa6da984f8d0ac955

Polysign and Standard Custody will not be the same thing, but they'll definitely have important interactions.
My guess is that while Polysign will develop a provide infrastructure, Standard Custody will be a charter holding a custodian license.
Yeah, seems like Standard Custody applied for a license before NY Department of Financial services back in September, 2019.
https://www.dfs.ny.gov/reports_and_publications/weekly_bulletins/wb20190920
https://www.dfs.ny.gov/reports_and_publications/weekly_bulletins/wb20190920