Purchase Agreement Workflow - No value or quantity on agreement line

Hello,

I'm trying to create a workflow for purchase agreements to flow through, however, I'm having trouble due to the lack of options when creating conditional decisions.

I'm basing my PA workflow on a workflow that I've create for purchase orders - in this PO workflow I've used a conditional decision,

"Where Purchase orders.Invoice amount < value 5000.00 GBP".

I'd like to use something very similar for my PA workflow, where I could use the quantity or value of the agreement line, but the conditions for conditional decisions are very limited.

Has anyone had any experience of setting up a Purchase agreement workflow in a similar way to this or found a workaround that would suffice?

Thanks & Kind Regards,

Josh