Today there are three general JFR GC event tests:
triggers many GCs by calling System.gc()
triggers many GCs by allocating lot's of memory
triggers even more GC by doing what TestGCEventExplicit and TestGCEventImplict at the same time.
Since these tests run for all the different collectors they are very time consuming and the purpose of the unit tests is to verify the data, not stress the system, the TestGCEventAll shoud be sufficient.