In SRP2Core 2021.1.3f1.2299, graph will throw exceptions/softlock which will lose unsaved progress on that graph.
7.3.1: repeated enum pasting will cause Unity to hang and take up lots of memory/power but the threshold to cause this is much higher than what will cause later versions to crash. Unity will not throw exceptions either like in 2021.1.
In SRP2Core 2021.2.0a16.2250, 5 enum keywords are enough to cause Unity to crash.

Since the consequences are more severe in later versions, I have labeled this as a regression.

Repro steps:
1. Open a shadergraph
2. Keep creating enum keywords until Unity crashes
Expected result: Unity keeps you from creating too many keywords
Actual result: Unity crashes