Tbf isn't the old way the same as all items and blocks?
If the blockstate or item file has a misconfigured model or texture, only that entry fails?
It just shows the good ol' purle and black cube.
It lets you know exactly what is wrong, rather than needing to check a log as you know what you tried to use.
It was always the same case aswell, if a unicode failed to load you knew where the issue was.
Now you have to do roundabout ways to figure it out instead of just knowing right then and there
Seems it was a resourcepack i had on somehow...
Sorry