Another good use of transaction mode from clish would be trying to copy/paste a large number of commands directly into a SSH-based clish session. When copy/pasting very large sets of commands I have seen situations where characters get dropped and cause a syntax error with some of the commands. Rather than having some of them take effect instantly and others not work (leading to strange problems), one could paste them in transaction mode (thus delaying their activation), scroll back up to ensure they were no errors displayed, then commit them if everything looks OK. If there were errors just rollback the transaction, start a new one then paste a smaller number of commands (or correct whatever legit syntax errors you had in what you were pasting).
Or better yet just use load configuration and avoid copy/pasting entirely...
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