So I'm a little confused on Orion 2017.3 Hotfix 4: this shows updated January 30, 2018.
Orion Platform 2017.3 Hotfix 4 - SolarWinds Worldwide, LLC. Help and Support
However it looks like I already have Hotfix 4 applied back on the 11th of Jan? Does the above date of Jan 30th just relate to when the hot fix release notes were updated?
Yes, it is a document update.