Enabled Path /Library/Pd :

/Users/user_name/Library/Pd // Doesn't exist

@Il-pleut Well that was a waste of time....... although I learnt quite a lot of tcl.
I built a plugin to disable externals but......
If a patch containing externals is opened then Pd will not search for them again when it is reopened.
They are held in memory for re-use.
So you might as well use the command line switch -nostdpath to turn them off as Pd starts.
David.