I think it's more fair to call it a distinguisher of American English vs. British English.
Even just reading "I've a train to catch" gives a British accent in my mind.
A particular part of Britain as well. I have never used “I’ve” in that way ( I speak more RP than with an accent)
A particular part of Britain as well. I have never used “I’ve” in that way ( I speak more RP than with an accent)