I've not "untied" mine yet (and it's been a couple months) and nothing bad has happened, but I'm following your post to see if someone knows the answer
The stems would be permanent, unfortunately, cause they became woody. But the plant doesn't mind. Note that over time the individual stems might grow away from each other. At this stage, you can cut back the stems to where thay are braided, and new shoots should grow, or you can tie them together
So I believe at some point you should take it off once they have become woody and intertwined so it doesnβt cut into the plant. Like you can continue to braid it and tie it but move the tie up so it doesnβt strangle the plant.