...And investigate why it doesn't work.
Each StorageTimestampTest starts with a block that excludes non-WT storage engines.
I believe the code can refer to supporting snapshot reads instead, e.g:
// Only run on storage engine's that support snapshot reads. if (!_opCtx->getServiceContext()->getStorageEngine()->supportsReadConcernSnapshot()) { return; }
However, a quick check showed Enterprise's inMemory failed the SecondaryInsertTimes test. I didn't try running the others.