Hi,
From what I've seen, IFS Cloud doesn't have a native, general-purpose customer satisfaction or NPS module out of the box. There isn't a standard "survey" object designed for sending something out to an external customer and tracking responses centrally.
What IFS Cloud does have is the Maintenance Surveys (eForm) functionality, but that's scoped to maintenance/service work — it's answered ad-hoc by technicians through MWO or the Technician Portal, tied to work tasks and objects. It's not built for triggering off something like an order being marked Invoiced, and it's not meant to be sent externally to a customer.
One other thing I'd flag: it sounds like the real pain point might be less "which survey tool" and more "how reliably is the Invoiced trigger being published out of IFS." If your current integration is polling or using a fragile point-to-point connection, it may be worth having your technical team look at wiring that trigger through IFS Cloud's Business Event/Event Action framework instead — a proper event-driven publish on Invoiced tends to be far more reliable than whatever's failing now, regardless of which survey tool sits on the receiving end.