IT promise to business: "You can use RPA if we tell you we can't build a thing in time."
Business promise to IT: "We'll turn off RPA at such time as you deliver us a working solution."
And then be very particular that business needs to have documentation of their RPA in order to implement in production (business process / ask, notsomuch technical).
This accomplishes a few positive things: (1) takes {insert dumb / hard / bad ROI business request off IT's priority plate}, (2) forces business to think about what they actually want, (3) forces business to document what they actually want, (4) provides business the flexibility to change their automation, when the realize they don't want what they thought they wanted, & (5) burns not-developer time learning all the intricacies and quirks of {legacy software / website / data}.
In the end, when IT comes back around knocking, their business counterparts actually have gasp documentation. And furthermore, documentation that's actually been battle tested and seen prod systems & data.
(It's an admittance that most IT projects fail not for lack of technical feasibility, but for incomplete or shifting specs)