"Delayed action increases challenges to both economic and societal feasibility after 2030"

This is coming from the historically conservative IPCC. They're still incorporating carbon capture technology that doesn't exist or doesn't exist at scale in projections (see C2.4 on page 17 of the PDF). While they admit in C8.2 (page 23) that these technologies are still in pilot stages and require commercialization, I would have liked there to have been more analysis of the risk that these technologies won't work at scale in section C10. Is it a near certainty we figure CCS out and the challenges are political and economic, or are there uncertain scientific and engineering challenges that remain?