I just updated to macOS 10.14.3 with the Delta, and it went smoothly and quickly.

I forgot to time the process (for a change ), but I don't think it took 10 minutes from the time the progress bar told me 40 to go...maybe 20 minutes for the entire installation process...maybe not even.

Safari updated to v 12.0.3, but I haven't noticed any difference.

No glitches in the early going.

Download macOS Mojave 10.14.3 Combo Update

Here's a weird one:

I downloaded the Combo 10.14.3 Update and tried to install it, but got a message that my internal disk (not to mention the externals) did not meet the requirements for the update. I then went to Software Update and it said that my 10.14.2 system was up to date.

Upon restart, the Combo gave me the same message but SU was able to download and install the Delta update. After installation, I opened the Combo and was given the green light in case I wanted to install it over my 10.14.3 system. (I won't do that unless I notice some issues.)

Any ideas?

I have a couple of suggestions...

1. Run the latest version of Etrecheck and see what, if any, major and/or minor issues show up there
2. Carefully document the sequence of events
   1. call Apple Tech Support and report the incident . (You have a solution for this update, but you are seeking to prevent its recurrence with MacOS 10.14.4 when it is released)
   2. If you don't get a satisfactory answer, request the incident be escalated.
   3. Since you already have the issue carefully documented submit a a trouble report

This issue with the 10.14.3 Combo updater appears to be an error in the distribution file. The ‘workaround’ via the delta updater is a good one, perhaps to be superseded by the next Combo updater.

Thanks to both Alternaut and Joe. It's good to know that my system is not at fault.

If you've missed it, the macOS Mojave 10.14.3 Supplemental Update has been available for a couple of days.

Updated 10.14.3 Delta and Combo updaters have also been released.

I installed the supplemental update today. No issues.