The camera FW updates do not always contain FW updates for all cameras, and are very camera specific.
Camera FW 4.8 is the latest FW update for the UM 4.6. FW 5.1.1 does contain an update for thr Ursa Viewfinder (EVF), and after running the update on your Camera, connect and uodatemth FW on the EVF.
You need to read the update notes, it will tell you which cameras the update is for. The notes for FW 5.1.1 state:
What's new in Blackmagic Camera Setup 5.1.1
New features for URSA Broadcast
Smoother, faster iris control for B4 and PL servo lenses from camera.
Smoother, faster iris control for EF 'Hybrid Compact Servo’ lenses.
Smoother, faster iris control for servo lenses via SDI Camera Control.
Fixed ‘status text’ bug for Viewfinder & Studio Viewfinder ‘clean feed’.
Updated URSA Broadcast manual recommended CFast, SD and SSD list.
New features for URSA Mini Pro
Smoother, faster iris control for B4 and PL servo lenses from camera.
Smoother, faster iris control for EF 'Hybrid Compact Servo’ lenses.
Smoother, faster iris control for servo lenses via SDI Camera Control.
Fixed Quicktime compatability bug with some third party NLE’s.
Fixed ‘status text’ bug for Viewfinder & Studio Viewfinder ‘clean feed’.
Fixed menu freeze that occurs when selecting 3K Anamorphic and 4.6K 2.4:1.
Updated URSA Mini manual recommended CFast, SD and SSD list.
New features for URSA Studio Viewfinder
Support for smooth iris readout on Studio Viewfinder ‘status text’.
Adds support for ‘fiber’ logo in UI when powered from SMPTE fiber.
New features for URSA Viewfinder
Support for smooth iris readout on Viewfinder ‘status text’.
Adds support for ‘fiber’ logo in UI when powered from SMPTE fiber.
No new features in 5.1.1 for other camera products.
Cheers