Just wanted to bump this as I believe uBlock Origin Lite has reached a level of stability that it should be added as an option alongside AdGuard for Safari. Since my last comment, Gorhill has implemented fixes so the start-up issues noted above have been resolved.
It seems the primary issue is that due to Safari restrictions, WebExtensions like uBOL do not work on web apps or in-app webpages. Other than that, I have noticed that uBOL “feels” less resource heavy than AdGuard. But this is not based on any exact benchmarks.
uBlock Origin Lite has an advantage over AdGuard in being “set and forget” while also offering support for uBlock specific filters by default alongside the usual Easylist options.
While I believe that the AdGuard recommendation is fine to remain, uBOL has reached a level of stability on Safari that it should be added as a secondary option for iOS and Mac users.