Text expanders are great. If you send the same shipping policy, intro line or meeting link twenty times a day, a snippet saves real time and nobody minds getting the same words.
They go wrong when a snippet lands in a conversation that needed an answer, not a template. The other person asked something specific, and they got your standard paragraph back.
The test is one question: would the right reply be the same if a different person had sent this?
A useful middle step is to keep snippets for the facts and write the first sentence yourself. "Good question about the March dates. Here's the full schedule:" plus the snippet reads like a person replied.
If you want the tool side of this, here's a fair comparison of Text Blaze and Grais for templated versus thread-aware replies. It says plainly where Text Blaze is the better pick.