Can you re-crimp the end of a PEX tube?
I think that you'd  probably have to ask your Pex manufacturer to get an official answer as to whether or not this is recommended.  But I can say based on personal experience that I've occasionally done what you propose without issue. And if you try it and it turns out not to work because the connection leaks, it will only have cost you a ~$0.50 crimp ring, plus however long it took you to cut off the original ring.