Hello Dav1,
Most (but not all) SKD’s documentation have a MCUXpresso SDK Change Log which covers very briefly what changes have been applied to that SDK. I would recommend going to the MCUXpresso Builder and downloading the SDK documentation for your desired SDK.
I agree that this is not the most efficient way to access this information, my apologies for this.
I hope that this information helps!
Regards,
Gustavo