Here’s a sample file demonstrating 1st x only. There’s a hidden “Tacet” PT at the end of the first ending which triggers a channel change to a channel without a VST instrument. The “Play” in the 2nd ending switches it back.
If you wanted 2nd x only, I think you’d need to trigger the Tacet right before the initial repeat sign, then put the Play in the 1st ending or right before the ending repeat.
1st x Only.dorico (444.4 KB)