Has 朅 (qiè) ever been commonly used for 去 'to go'
I think this Zhihu post might be of help.

To sum up:


Not just southwest, many topolects, including even the good old Beijing dialect, read 去 along the lines of qie or khe.
The OP's quoted text used the character 朅, probably to distinguish it from the standard mandarin qu, but in fact it is just 去 but with a different sound.