Its normal for the engine to “get stuck” on loading into a new version, it pre-generates the derived data cache to speed up future engine work, unless something is terribly broken you need to just wait it out on that first load.
As for your custom blueprint library, you can’t just copy paste nodes over, you need to include the correct modules that contain the referenced classes as well as include the headers for them.
Also the platform checks don’t hurt anything, they are pre-compile step removed if on the correct platform, the logging is also very little perf and lets you know when you have something incorrect, you should be doing the pointer validation REGARDLESS of if you are logging on fail or not, just to ensure stability.