[XeTeX] Reducing ligatures in arabxetex

[Juan Acevedo]

Hello,

The package arabtex has a handy switch to reduce the number of Arabic ligatures used: you can alternate between the essential ligatures (\ligsfalse) or having additionally stacking letters (\ligstrue).

Now I'm working with arabxetex. I have to set some pages of Persian, I realise that Persian typesetting is sparing in its use of ligatures and I would like to reduce them to a minimum, like avoiding stacking letters. Is there any way to achieve that \ligsfalse effect in arabxetex, or any dirty trick to that effect someone might like to share?

I have searched all over and I have been trying unsuccessfully the different combinations of fontspec Ligatures settings. 

Thanks for any help or hint,
Juan