Why can't you intergrate inventory limit in Paypal

I have multiple products that people can purchase but each has a limit of 120. I don't want to use inventory plus form calculation because then my accounting dept will have to jump through hoops to try to figure of which item is which. Can you look into doing a limit in the Paypal integration? Here is my form https://form.jotform.com/52995495869179

This seems to be a nice feature to be added in the near future, for now our current integration does not have this enabled.