Will Safari Technology Preview Version 188 fix the signed issue or it useless?
Yes, that version appears to be properly signed. But as mentioned before, Safari Technology Preview doesn’t replace the release version, it installs alongside it. So you will still have Safari 17.3 18617.2.4.11.11 and Safari Technology Preview 17.4 18619.1.2.1.1.
If you want to replace 17.3 18617.2.4.11.11, you can install the beta version 17.4 (18618.1.13.11.5)
Code:
https://swcdn.apple.com/content/downloads/22/07/052-49201-A_HXGXTKN01O/4chpvhyilgwr8ifjj76jn03x3hvres2c9t/Safari17.4VenturaAutoSeed.pkg
As you can’t uninstall the beta version, only install a newer beta or the release, I think it’s probably best to wait for Apple to release Safari 17.4.
I do not understand the term WebKit when it refers "Safari Technology Preview includes the latest WebKit enhancements." Can you use another words for me to understand please?
WebKit is the internal engine of Safari, responsible for interpreting the code of webpages and displaying it. New features are tested first in Safari Technology Preview, then implemented in Safari Beta and finally in the release version of Safari.
If you turn on “Show features for web developers” in Safari, you will see the Feature Flags settings in Safari Settings, where Apple lists the features that are Stable, Testable or in Preview.
https://support.apple.com/guide/safari/ibrw1075/17.0/mac/13.0